WCSLIB: wcs.h Source File

WCSLIB 7.12

wcs.h
Go to the documentation of this file.
1/*============================================================================
2 WCSLIB 7.12 - an implementation of the FITS WCS standard.
3 Copyright (C) 1995-2022, Mark Calabretta
4
5 This file is part of WCSLIB.
6
7 WCSLIB is free software: you can redistribute it and/or modify it under the
8 terms of the GNU Lesser General Public License as published by the Free
9 Software Foundation, either version 3 of the License, or (at your option)
10 any later version.
11
12 WCSLIB is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
15 more details.
16
17 You should have received a copy of the GNU Lesser General Public License
18 along with WCSLIB. If not, see http://www.gnu.org/licenses.
19
20 Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
21 http://www.atnf.csiro.au/people/Mark.Calabretta
22 $Id: wcs.h,v 7.12 2022/09/09 04:57:58 mcalabre Exp $
23*=============================================================================
24*
25* WCSLIB 7.12 - C routines that implement the FITS World Coordinate System
26* (WCS) standard. Refer to the README file provided with WCSLIB for an
27* overview of the library.
28*
29*
30* Summary of the wcs routines
31* ---------------------------
32* Routines in this suite implement the FITS World Coordinate System (WCS)
33* standard which defines methods to be used for computing world coordinates
34* from image pixel coordinates, and vice versa. The standard, and proposed
35* extensions for handling distortions, are described in
36*
37= "Representations of world coordinates in FITS",
38= Greisen, E.W., & Calabretta, M.R. 2002, A&A, 395, 1061 (WCS Paper I)
39=
40= "Representations of celestial coordinates in FITS",
41= Calabretta, M.R., & Greisen, E.W. 2002, A&A, 395, 1077 (WCS Paper II)
42=
43= "Representations of spectral coordinates in FITS",
44= Greisen, E.W., Calabretta, M.R., Valdes, F.G., & Allen, S.L.
45= 2006, A&A, 446, 747 (WCS Paper III)
46=
47= "Representations of distortions in FITS world coordinate systems",
48= Calabretta, M.R. et al. (WCS Paper IV, draft dated 2004/04/22),
49= available from http://www.atnf.csiro.au/people/Mark.Calabretta
50=
51= "Mapping on the HEALPix grid",
52= Calabretta, M.R., & Roukema, B.F. 2007, MNRAS, 381, 865 (WCS Paper V)
53=
54= "Representing the 'Butterfly' Projection in FITS -- Projection Code XPH",
55= Calabretta, M.R., & Lowe, S.R. 2013, PASA, 30, e050 (WCS Paper VI)
56=
57= "Representations of time coordinates in FITS -
58= Time and relative dimension in space",
59= Rots, A.H., Bunclark, P.S., Calabretta, M.R., Allen, S.L.,
60= Manchester, R.N., & Thompson, W.T. 2015, A&A, 574, A36 (WCS Paper VII)
61*
62* These routines are based on the wcsprm struct which contains all information
63* needed for the computations. The struct contains some members that must be
64* set by the user, and others that are maintained by these routines, somewhat
65* like a C++ class but with no encapsulation.
66*
67* wcsnpv(), wcsnps(), wcsini(), wcsinit(), wcssub(), wcsfree(), and wcstrim(),
68* are provided to manage the wcsprm struct, wcssize() computes its total size
69* including allocated memory, and wcsprt() prints its contents. Refer to the
70* description of the wcsprm struct for an explanation of the anticipated usage
71* of these routines. wcscopy(), which does a deep copy of one wcsprm struct
72* to another, is defined as a preprocessor macro function that invokes
73* wcssub().
74*
75* wcsperr() prints the error message(s) (if any) stored in a wcsprm struct,
76* and the linprm, celprm, prjprm, spcprm, and tabprm structs that it contains.
77*
78* A setup routine, wcsset(), computes intermediate values in the wcsprm struct
79* from parameters in it that were supplied by the user. The struct always
80* needs to be set up by wcsset() but this need not be called explicitly -
81* refer to the explanation of wcsprm::flag.
82*
83* wcsp2s() and wcss2p() implement the WCS world coordinate transformations.
84* In fact, they are high level driver routines for the WCS linear,
85* logarithmic, celestial, spectral and tabular transformation routines
86* described in lin.h, log.h, cel.h, spc.h and tab.h.
87*
88* Given either the celestial longitude or latitude plus an element of the
89* pixel coordinate a hybrid routine, wcsmix(), iteratively solves for the
90* unknown elements.
91*
92* wcsccs() changes the celestial coordinate system of a wcsprm struct, for
93* example, from equatorial to galactic, and wcssptr() translates the spectral
94* axis. For example, a 'FREQ' axis may be translated into 'ZOPT-F2W' and vice
95* versa.
96*
97* wcslib_version() returns the WCSLIB version number.
98*
99* Quadcube projections:
100* ---------------------
101* The quadcube projections (TSC, CSC, QSC) may be represented in FITS in
102* either of two ways:
103*
104* a: The six faces may be laid out in one plane and numbered as follows:
105*
106= 0
107=
108= 4 3 2 1 4 3 2
109=
110= 5
111*
112* Faces 2, 3 and 4 may appear on one side or the other (or both). The
113* world-to-pixel routines map faces 2, 3 and 4 to the left but the
114* pixel-to-world routines accept them on either side.
115*
116* b: The "COBE" convention in which the six faces are stored in a
117* three-dimensional structure using a CUBEFACE axis indexed from
118* 0 to 5 as above.
119*
120* These routines support both methods; wcsset() determines which is being
121* used by the presence or absence of a CUBEFACE axis in ctype[]. wcsp2s()
122* and wcss2p() translate the CUBEFACE axis representation to the single
123* plane representation understood by the lower-level WCSLIB projection
124* routines.
125*
126*
127* wcsnpv() - Memory allocation for PVi_ma
128* ---------------------------------------
129* wcsnpv() sets or gets the value of NPVMAX (default 64). This global
130* variable controls the number of pvcard structs, for holding PVi_ma
131* keyvalues, that wcsini() should allocate space for. It is also used by
132* wcsinit() as the default value of npvmax.
133*
134* PLEASE NOTE: This function is not thread-safe.
135*
136* Given:
137* n int Value of NPVMAX; ignored if < 0. Use a value less
138* than zero to get the current value.
139*
140* Function return value:
141* int Current value of NPVMAX.
142*
143*
144* wcsnps() - Memory allocation for PSi_ma
145* ---------------------------------------
146* wcsnps() sets or gets the value of NPSMAX (default 8). This global variable
147* controls the number of pscard structs, for holding PSi_ma keyvalues, that
148* wcsini() should allocate space for. It is also used by wcsinit() as the
149* default value of npsmax.
150*
151* PLEASE NOTE: This function is not thread-safe.
152*
153* Given:
154* n int Value of NPSMAX; ignored if < 0. Use a value less
155* than zero to get the current value.
156*
157* Function return value:
158* int Current value of NPSMAX.
159*
160*
161* wcsini() - Default constructor for the wcsprm struct
162* ----------------------------------------------------
163* wcsini() is a thin wrapper on wcsinit(). It invokes it with npvmax,
164* npsmax, and ndpmax set to -1 which causes it to use the values of the
165* global variables NDPMAX, NPSMAX, and NDPMAX. It is thereby potentially
166* thread-unsafe if these variables are altered dynamically via wcsnpv(),
167* wcsnps(), and disndp(). Use wcsinit() for a thread-safe alternative in
168* this case.
169*
170*
171* wcsinit() - Default constructor for the wcsprm struct
172* -----------------------------------------------------
173* wcsinit() optionally allocates memory for arrays in a wcsprm struct and sets
174* all members of the struct to default values.
175*
176* PLEASE NOTE: every wcsprm struct should be initialized by wcsinit(),
177* possibly repeatedly. On the first invokation, and only the first
178* invokation, wcsprm::flag must be set to -1 to initialize memory management,
179* regardless of whether wcsinit() will actually be used to allocate memory.
180*
181* Given:
182* alloc int If true, allocate memory unconditionally for the
183* crpix, etc. arrays. Please note that memory is never
184* allocated by wcsinit() for the auxprm, tabprm, nor
185* wtbarr structs.
186*
187* If false, it is assumed that pointers to these arrays
188* have been set by the user except if they are null
189* pointers in which case memory will be allocated for
190* them regardless. (In other words, setting alloc true
191* saves having to initalize these pointers to zero.)
192*
193* naxis int The number of world coordinate axes. This is used to
194* determine the length of the various wcsprm vectors and
195* matrices and therefore the amount of memory to
196* allocate for them.
197*
198* Given and returned:
199* wcs struct wcsprm*
200* Coordinate transformation parameters.
201*
202* Note that, in order to initialize memory management,
203* wcsprm::flag should be set to -1 when wcs is
204* initialized for the first time (memory leaks may
205* result if it had already been initialized).
206*
207* Given:
208* npvmax int The number of PVi_ma keywords to allocate space for.
209* If set to -1, the value of the global variable NPVMAX
210* will be used. This is potentially thread-unsafe if
211* wcsnpv() is being used dynamically to alter its value.
212*
213* npsmax int The number of PSi_ma keywords to allocate space for.
214* If set to -1, the value of the global variable NPSMAX
215* will be used. This is potentially thread-unsafe if
216* wcsnps() is being used dynamically to alter its value.
217*
218* ndpmax int The number of DPja or DQia keywords to allocate space
219* for. If set to -1, the value of the global variable
220* NDPMAX will be used. This is potentially
221* thread-unsafe if disndp() is being used dynamically to
222* alter its value.
223*
224* Function return value:
225* int Status return value:
226* 0: Success.
227* 1: Null wcsprm pointer passed.
228* 2: Memory allocation failed.
229*
230* For returns > 1, a detailed error message is set in
231* wcsprm::err if enabled, see wcserr_enable().
232*
233*
234* wcsauxi() - Default constructor for the auxprm struct
235* -----------------------------------------------------
236* wcsauxi() optionally allocates memory for an auxprm struct, attaches it to
237* wcsprm, and sets all members of the struct to default values.
238*
239* Given:
240* alloc int If true, allocate memory unconditionally for the
241* auxprm struct.
242*
243* If false, it is assumed that wcsprm::aux has already
244* been set to point to an auxprm struct, in which case
245* the user is responsible for managing that memory.
246* However, if wcsprm::aux is a null pointer, memory will
247* be allocated regardless. (In other words, setting
248* alloc true saves having to initalize the pointer to
249* zero.)
250*
251* Given and returned:
252* wcs struct wcsprm*
253* Coordinate transformation parameters.
254*
255* Function return value:
256* int Status return value:
257* 0: Success.
258* 1: Null wcsprm pointer passed.
259* 2: Memory allocation failed.
260*
261*
262* wcssub() - Subimage extraction routine for the wcsprm struct
263* ------------------------------------------------------------
264* wcssub() extracts the coordinate description for a subimage from a wcsprm
265* struct. It does a deep copy, using wcsinit() to allocate memory for its
266* arrays if required. Only the "information to be provided" part of the
267* struct is extracted. Consequently, wcsset() need not have been, and won't
268* be invoked on the struct from which the subimage is extracted. A call to
269* wcsset() is required to set up the subimage struct.
270*
271* The world coordinate system of the subimage must be separable in the sense
272* that the world coordinates at any point in the subimage must depend only on
273* the pixel coordinates of the axes extracted. In practice, this means that
274* the linear transformation matrix of the original image must not contain
275* non-zero off-diagonal terms that associate any of the subimage axes with any
276* of the non-subimage axes. Likewise, if any distortions are associated with
277* the subimage axes, they must not depend on any of the axes that are not
278* being extracted.
279*
280* Note that while the required elements of the tabprm array are extracted, the
281* wtbarr array is not. (Thus it is not appropriate to call wcssub() after
282* wcstab() but before filling the tabprm structs - refer to wcshdr.h.)
283*
284* wcssub() can also add axes to a wcsprm struct. The new axes will be created
285* using the defaults set by wcsinit() which produce a simple, unnamed, linear
286* axis with world coordinate equal to the pixel coordinate. These default
287* values can be changed afterwards, before invoking wcsset().
288*
289* Given:
290* alloc int If true, allocate memory for the crpix, etc. arrays in
291* the destination. Otherwise, it is assumed that
292* pointers to these arrays have been set by the user
293* except if they are null pointers in which case memory
294* will be allocated for them regardless.
295*
296* wcssrc const struct wcsprm*
297* Struct to extract from.
298*
299* Given and returned:
300* nsub int*
301* axes int[] Vector of length *nsub containing the image axis
302* numbers (1-relative) to extract. Order is
303* significant; axes[0] is the axis number of the input
304* image that corresponds to the first axis in the
305* subimage, etc.
306*
307* Use an axis number of 0 to create a new axis using
308* the defaults set by wcsinit(). They can be changed
309* later.
310*
311* nsub (the pointer) may be set to zero, and so also may
312* *nsub, which is interpreted to mean all axes in the
313* input image; the number of axes will be returned if
314* nsub != 0x0. axes itself (the pointer) may be set to
315* zero to indicate the first *nsub axes in their
316* original order.
317*
318* Set both nsub (or *nsub) and axes to zero to do a deep
319* copy of one wcsprm struct to another.
320*
321* Subimage extraction by coordinate axis type may be
322* done by setting the elements of axes[] to the
323* following special preprocessor macro values:
324*
325* WCSSUB_LONGITUDE: Celestial longitude.
326* WCSSUB_LATITUDE: Celestial latitude.
327* WCSSUB_CUBEFACE: Quadcube CUBEFACE axis.
328* WCSSUB_SPECTRAL: Spectral axis.
329* WCSSUB_STOKES: Stokes axis.
330* WCSSUB_TIME: Time axis.
331*
332* Refer to the notes (below) for further usage examples.
333*
334* On return, *nsub will be set to the number of axes in
335* the subimage; this may be zero if there were no axes
336* of the required type(s) (in which case no memory will
337* be allocated). axes[] will contain the axis numbers
338* that were extracted, or 0 for newly created axes. The
339* vector length must be sufficient to contain all axis
340* numbers. No checks are performed to verify that the
341* coordinate axes are consistent, this is done by
342* wcsset().
343*
344* wcsdst struct wcsprm*
345* Struct describing the subimage. wcsprm::flag should
346* be set to -1 if wcsdst was not previously initialized
347* (memory leaks may result if it was previously
348* initialized).
349*
350* Function return value:
351* int Status return value:
352* 0: Success.
353* 1: Null wcsprm pointer passed.
354* 2: Memory allocation failed.
355* 12: Invalid subimage specification.
356* 13: Non-separable subimage coordinate system.
357*
358* For returns > 1, a detailed error message is set in
359* wcsprm::err if enabled, see wcserr_enable().
360*
361* Notes:
362* 1: Combinations of subimage axes of particular types may be extracted in
363* the same order as they occur in the input image by combining
364* preprocessor codes, for example
365*
366= *nsub = 1;
367= axes[0] = WCSSUB_LONGITUDE | WCSSUB_LATITUDE | WCSSUB_SPECTRAL;
368*
369* would extract the longitude, latitude, and spectral axes in the same
370* order as the input image. If one of each were present, *nsub = 3 would
371* be returned.
372*
373* For convenience, WCSSUB_CELESTIAL is defined as the combination
374* WCSSUB_LONGITUDE | WCSSUB_LATITUDE | WCSSUB_CUBEFACE.
375*
376* The codes may also be negated to extract all but the types specified,
377* for example
378*
379= *nsub = 4;
380= axes[0] = WCSSUB_LONGITUDE;
381= axes[1] = WCSSUB_LATITUDE;
382= axes[2] = WCSSUB_CUBEFACE;
383= axes[3] = -(WCSSUB_SPECTRAL | WCSSUB_STOKES);
384*
385* The last of these specifies all axis types other than spectral or
386* Stokes. Extraction is done in the order specified by axes[] a
387* longitude axis (if present) would be extracted first (via axes[0]) and
388* not subsequently (via axes[3]). Likewise for the latitude and cubeface
389* axes in this example.
390*
391* From the foregoing, it is apparent that the value of *nsub returned may
392* be less than or greater than that given. However, it will never exceed
393* the number of axes in the input image (plus the number of newly-created
394* axes if any were specified on input).
395*
396*
397* wcscompare() - Compare two wcsprm structs for equality
398* ------------------------------------------------------
399* wcscompare() compares two wcsprm structs for equality.
400*
401* Given:
402* cmp int A bit field controlling the strictness of the
403* comparison. When 0, all fields must be identical.
404*
405* The following constants may be or'ed together to
406* relax the comparison:
407* WCSCOMPARE_ANCILLARY: Ignore ancillary keywords
408* that don't change the WCS transformation, such
409* as DATE-OBS or EQUINOX.
410* WCSCOMPARE_TILING: Ignore integral differences in
411* CRPIXja. This is the 'tiling' condition, where
412* two WCSes cover different regions of the same
413* map projection and align on the same map grid.
414* WCSCOMPARE_CRPIX: Ignore any differences at all in
415* CRPIXja. The two WCSes cover different regions
416* of the same map projection but may not align on
417* the same map grid. Overrides WCSCOMPARE_TILING.
418*
419* tol double Tolerance for comparison of floating-point values.
420* For example, for tol == 1e-6, all floating-point
421* values in the structs must be equal to the first 6
422* decimal places. A value of 0 implies exact equality.
423*
424* wcs1 const struct wcsprm*
425* The first wcsprm struct to compare.
426*
427* wcs2 const struct wcsprm*
428* The second wcsprm struct to compare.
429*
430* Returned:
431* equal int* Non-zero when the given structs are equal.
432*
433* Function return value:
434* int Status return value:
435* 0: Success.
436* 1: Null pointer passed.
437*
438*
439* wcscopy() macro - Copy routine for the wcsprm struct
440* ----------------------------------------------------
441* wcscopy() does a deep copy of one wcsprm struct to another. As of
442* WCSLIB 3.6, it is implemented as a preprocessor macro that invokes
443* wcssub() with the nsub and axes pointers both set to zero.
444*
445*
446* wcsfree() - Destructor for the wcsprm struct
447* --------------------------------------------
448* wcsfree() frees memory allocated for the wcsprm arrays by wcsinit() and/or
449* wcsset(). wcsinit() records the memory it allocates and wcsfree() will only
450* attempt to free this.
451*
452* PLEASE NOTE: wcsfree() must not be invoked on a wcsprm struct that was not
453* initialized by wcsinit().
454*
455* Given and returned:
456* wcs struct wcsprm*
457* Coordinate transformation parameters.
458*
459* Function return value:
460* int Status return value:
461* 0: Success.
462* 1: Null wcsprm pointer passed.
463*
464*
465* wcstrim() - Free unused arrays in the wcsprm struct
466* ---------------------------------------------------
467* wcstrim() frees memory allocated by wcsinit() for arrays in the wcsprm
468* struct that remains unused after it has been set up by wcsset().
469*
470* The free'd array members are associated with FITS WCS keyrecords that are
471* rarely used and usually just bloat the struct: wcsprm::crota, wcsprm::colax,
472* wcsprm::cname, wcsprm::crder, wcsprm::csyer, wcsprm::czphs, and
473* wcsprm::cperi. If unused, wcsprm::pv, wcsprm::ps, and wcsprm::cd are also
474* freed.
475*
476* Once these arrays have been freed, a test such as
477=
478= if (!undefined(wcs->cname[i])) {...}
479=
480* must be protected as follows
481=
482= if (wcs->cname && !undefined(wcs->cname[i])) {...}
483=
484* In addition, if wcsprm::npv is non-zero but less than wcsprm::npvmax, then
485* the unused space in wcsprm::pv will be recovered (using realloc()).
486* Likewise for wcsprm::ps.
487*
488* Given and returned:
489* wcs struct wcsprm*
490* Coordinate transformation parameters.
491*
492* Function return value:
493* int Status return value:
494* 0: Success.
495* 1: Null wcsprm pointer passed.
496* 14: wcsprm struct is unset.
497*
498*
499* wcssize() - Compute the size of a wcsprm struct
500* -----------------------------------------------
501* wcssize() computes the full size of a wcsprm struct, including allocated
502* memory.
503*
504* Given:
505* wcs const struct wcsprm*
506* Coordinate transformation parameters.
507*
508* If NULL, the base size of the struct and the allocated
509* size are both set to zero.
510*
511* Returned:
512* sizes int[2] The first element is the base size of the struct as
513* returned by sizeof(struct wcsprm). The second element
514* is the total allocated size, in bytes, assuming that
515* the allocation was done by wcsini(). This figure
516* includes memory allocated for members of constituent
517* structs, such as wcsprm::lin.
518*
519* It is not an error for the struct not to have been set
520* up via wcsset(), which normally results in additional
521* memory allocation.
522*
523* Function return value:
524* int Status return value:
525* 0: Success.
526*
527*
528* auxsize() - Compute the size of a auxprm struct
529* -----------------------------------------------
530* auxsize() computes the full size of a auxprm struct, including allocated
531* memory.
532*
533* Given:
534* aux const struct auxprm*
535* Auxiliary coordinate information.
536*
537* If NULL, the base size of the struct and the allocated
538* size are both set to zero.
539*
540* Returned:
541* sizes int[2] The first element is the base size of the struct as
542* returned by sizeof(struct auxprm). The second element
543* is the total allocated size, in bytes, currently zero.
544*
545* Function return value:
546* int Status return value:
547* 0: Success.
548*
549*
550* wcsprt() - Print routine for the wcsprm struct
551* ----------------------------------------------
552* wcsprt() prints the contents of a wcsprm struct using wcsprintf(). Mainly
553* intended for diagnostic purposes.
554*
555* Given:
556* wcs const struct wcsprm*
557* Coordinate transformation parameters.
558*
559* Function return value:
560* int Status return value:
561* 0: Success.
562* 1: Null wcsprm pointer passed.
563*
564*
565* wcsperr() - Print error messages from a wcsprm struct
566* -----------------------------------------------------
567* wcsperr() prints the error message(s), if any, stored in a wcsprm struct,
568* and the linprm, celprm, prjprm, spcprm, and tabprm structs that it contains.
569* If there are no errors then nothing is printed. It uses wcserr_prt(), q.v.
570*
571* Given:
572* wcs const struct wcsprm*
573* Coordinate transformation parameters.
574*
575* prefix const char *
576* If non-NULL, each output line will be prefixed with
577* this string.
578*
579* Function return value:
580* int Status return value:
581* 0: Success.
582* 1: Null wcsprm pointer passed.
583*
584*
585* wcsbchk() - Enable/disable bounds checking
586* ------------------------------------------
587* wcsbchk() is used to control bounds checking in the projection routines.
588* Note that wcsset() always enables bounds checking. wcsbchk() will invoke
589* wcsset() on the wcsprm struct beforehand if necessary.
590*
591* Given and returned:
592* wcs struct wcsprm*
593* Coordinate transformation parameters.
594*
595* Given:
596* bounds int If bounds&1 then enable strict bounds checking for the
597* spherical-to-Cartesian (s2x) transformation for the
598* AZP, SZP, TAN, SIN, ZPN, and COP projections.
599*
600* If bounds&2 then enable strict bounds checking for the
601* Cartesian-to-spherical (x2s) transformation for the
602* HPX and XPH projections.
603*
604* If bounds&4 then enable bounds checking on the native
605* coordinates returned by the Cartesian-to-spherical
606* (x2s) transformations using prjchk().
607*
608* Zero it to disable all checking.
609*
610* Function return value:
611* int Status return value:
612* 0: Success.
613* 1: Null wcsprm pointer passed.
614*
615*
616* wcsset() - Setup routine for the wcsprm struct
617* ----------------------------------------------
618* wcsset() sets up a wcsprm struct according to information supplied within
619* it (refer to the description of the wcsprm struct).
620*
621* wcsset() recognizes the NCP projection and converts it to the equivalent SIN
622* projection and likewise translates GLS into SFL. It also translates the
623* AIPS spectral types ('FREQ-LSR', 'FELO-HEL', etc.), possibly changing the
624* input header keywords wcsprm::ctype and/or wcsprm::specsys if necessary.
625*
626* Note that this routine need not be called directly; it will be invoked by
627* wcsp2s() and wcss2p() if the wcsprm::flag is anything other than a
628* predefined magic value.
629*
630* Given and returned:
631* wcs struct wcsprm*
632* Coordinate transformation parameters.
633*
634* Function return value:
635* int Status return value:
636* 0: Success.
637* 1: Null wcsprm pointer passed.
638* 2: Memory allocation failed.
639* 3: Linear transformation matrix is singular.
640* 4: Inconsistent or unrecognized coordinate axis
641* types.
642* 5: Invalid parameter value.
643* 6: Invalid coordinate transformation parameters.
644* 7: Ill-conditioned coordinate transformation
645* parameters.
646*
647* For returns > 1, a detailed error message is set in
648* wcsprm::err if enabled, see wcserr_enable().
649*
650* Notes:
651* 1: wcsset() always enables strict bounds checking in the projection
652* routines (via a call to prjini()). Use wcsbchk() to modify
653* bounds-checking after wcsset() is invoked.
654*
655*
656* wcsp2s() - Pixel-to-world transformation
657* ----------------------------------------
658* wcsp2s() transforms pixel coordinates to world coordinates.
659*
660* Given and returned:
661* wcs struct wcsprm*
662* Coordinate transformation parameters.
663*
664* Given:
665* ncoord,
666* nelem int The number of coordinates, each of vector length
667* nelem but containing wcs.naxis coordinate elements.
668* Thus nelem must equal or exceed the value of the
669* NAXIS keyword unless ncoord == 1, in which case nelem
670* is not used.
671*
672* pixcrd const double[ncoord][nelem]
673* Array of pixel coordinates.
674*
675* Returned:
676* imgcrd double[ncoord][nelem]
677* Array of intermediate world coordinates. For
678* celestial axes, imgcrd[][wcs.lng] and
679* imgcrd[][wcs.lat] are the projected x-, and
680* y-coordinates in pseudo "degrees". For spectral
681* axes, imgcrd[][wcs.spec] is the intermediate spectral
682* coordinate, in SI units.
683*
684* phi,theta double[ncoord]
685* Longitude and latitude in the native coordinate system
686* of the projection [deg].
687*
688* world double[ncoord][nelem]
689* Array of world coordinates. For celestial axes,
690* world[][wcs.lng] and world[][wcs.lat] are the
691* celestial longitude and latitude [deg]. For
692* spectral axes, imgcrd[][wcs.spec] is the intermediate
693* spectral coordinate, in SI units.
694*
695* stat int[ncoord]
696* Status return value for each coordinate:
697* 0: Success.
698* 1+: A bit mask indicating invalid pixel coordinate
699* element(s).
700*
701* Function return value:
702* int Status return value:
703* 0: Success.
704* 1: Null wcsprm pointer passed.
705* 2: Memory allocation failed.
706* 3: Linear transformation matrix is singular.
707* 4: Inconsistent or unrecognized coordinate axis
708* types.
709* 5: Invalid parameter value.
710* 6: Invalid coordinate transformation parameters.
711* 7: Ill-conditioned coordinate transformation
712* parameters.
713* 8: One or more of the pixel coordinates were
714* invalid, as indicated by the stat vector.
715*
716* For returns > 1, a detailed error message is set in
717* wcsprm::err if enabled, see wcserr_enable().
718*
719*
720* wcss2p() - World-to-pixel transformation
721* ----------------------------------------
722* wcss2p() transforms world coordinates to pixel coordinates.
723*
724* Given and returned:
725* wcs struct wcsprm*
726* Coordinate transformation parameters.
727*
728* Given:
729* ncoord,
730* nelem int The number of coordinates, each of vector length nelem
731* but containing wcs.naxis coordinate elements. Thus
732* nelem must equal or exceed the value of the NAXIS
733* keyword unless ncoord == 1, in which case nelem is not
734* used.
735*
736* world const double[ncoord][nelem]
737* Array of world coordinates. For celestial axes,
738* world[][wcs.lng] and world[][wcs.lat] are the
739* celestial longitude and latitude [deg]. For spectral
740* axes, world[][wcs.spec] is the spectral coordinate, in
741* SI units.
742*
743* Returned:
744* phi,theta double[ncoord]
745* Longitude and latitude in the native coordinate
746* system of the projection [deg].
747*
748* imgcrd double[ncoord][nelem]
749* Array of intermediate world coordinates. For
750* celestial axes, imgcrd[][wcs.lng] and
751* imgcrd[][wcs.lat] are the projected x-, and
752* y-coordinates in pseudo "degrees". For quadcube
753* projections with a CUBEFACE axis the face number is
754* also returned in imgcrd[][wcs.cubeface]. For
755* spectral axes, imgcrd[][wcs.spec] is the intermediate
756* spectral coordinate, in SI units.
757*
758* pixcrd double[ncoord][nelem]
759* Array of pixel coordinates.
760*
761* stat int[ncoord]
762* Status return value for each coordinate:
763* 0: Success.
764* 1+: A bit mask indicating invalid world coordinate
765* element(s).
766*
767* Function return value:
768* int Status return value:
769* 0: Success.
770* 1: Null wcsprm pointer passed.
771* 2: Memory allocation failed.
772* 3: Linear transformation matrix is singular.
773* 4: Inconsistent or unrecognized coordinate axis
774* types.
775* 5: Invalid parameter value.
776* 6: Invalid coordinate transformation parameters.
777* 7: Ill-conditioned coordinate transformation
778* parameters.
779* 9: One or more of the world coordinates were
780* invalid, as indicated by the stat vector.
781*
782* For returns > 1, a detailed error message is set in
783* wcsprm::err if enabled, see wcserr_enable().
784*
785*
786* wcsmix() - Hybrid coordinate transformation
787* -------------------------------------------
788* wcsmix(), given either the celestial longitude or latitude plus an element
789* of the pixel coordinate, solves for the remaining elements by iterating on
790* the unknown celestial coordinate element using wcss2p(). Refer also to the
791* notes below.
792*
793* Given and returned:
794* wcs struct wcsprm*
795* Indices for the celestial coordinates obtained
796* by parsing the wcsprm::ctype[].
797*
798* Given:
799* mixpix int Which element of the pixel coordinate is given.
800*
801* mixcel int Which element of the celestial coordinate is given:
802* 1: Celestial longitude is given in
803* world[wcs.lng], latitude returned in
804* world[wcs.lat].
805* 2: Celestial latitude is given in
806* world[wcs.lat], longitude returned in
807* world[wcs.lng].
808*
809* vspan const double[2]
810* Solution interval for the celestial coordinate [deg].
811* The ordering of the two limits is irrelevant.
812* Longitude ranges may be specified with any convenient
813* normalization, for example [-120,+120] is the same as
814* [240,480], except that the solution will be returned
815* with the same normalization, i.e. lie within the
816* interval specified.
817*
818* vstep const double
819* Step size for solution search [deg]. If zero, a
820* sensible, although perhaps non-optimal default will be
821* used.
822*
823* viter int If a solution is not found then the step size will be
824* halved and the search recommenced. viter controls how
825* many times the step size is halved. The allowed range
826* is 5 - 10.
827*
828* Given and returned:
829* world double[naxis]
830* World coordinate elements. world[wcs.lng] and
831* world[wcs.lat] are the celestial longitude and
832* latitude [deg]. Which is given and which returned
833* depends on the value of mixcel. All other elements
834* are given.
835*
836* Returned:
837* phi,theta double[naxis]
838* Longitude and latitude in the native coordinate
839* system of the projection [deg].
840*
841* imgcrd double[naxis]
842* Image coordinate elements. imgcrd[wcs.lng] and
843* imgcrd[wcs.lat] are the projected x-, and
844* y-coordinates in pseudo "degrees".
845*
846* Given and returned:
847* pixcrd double[naxis]
848* Pixel coordinate. The element indicated by mixpix is
849* given and the remaining elements are returned.
850*
851* Function return value:
852* int Status return value:
853* 0: Success.
854* 1: Null wcsprm pointer passed.
855* 2: Memory allocation failed.
856* 3: Linear transformation matrix is singular.
857* 4: Inconsistent or unrecognized coordinate axis
858* types.
859* 5: Invalid parameter value.
860* 6: Invalid coordinate transformation parameters.
861* 7: Ill-conditioned coordinate transformation
862* parameters.
863* 10: Invalid world coordinate.
864* 11: No solution found in the specified interval.
865*
866* For returns > 1, a detailed error message is set in
867* wcsprm::err if enabled, see wcserr_enable().
868*
869* Notes:
870* 1: Initially the specified solution interval is checked to see if it's a
871* "crossing" interval. If it isn't, a search is made for a crossing
872* solution by iterating on the unknown celestial coordinate starting at
873* the upper limit of the solution interval and decrementing by the
874* specified step size. A crossing is indicated if the trial value of the
875* pixel coordinate steps through the value specified. If a crossing
876* interval is found then the solution is determined by a modified form of
877* "regula falsi" division of the crossing interval. If no crossing
878* interval was found within the specified solution interval then a search
879* is made for a "non-crossing" solution as may arise from a point of
880* tangency. The process is complicated by having to make allowance for
881* the discontinuities that occur in all map projections.
882*
883* Once one solution has been determined others may be found by subsequent
884* invokations of wcsmix() with suitably restricted solution intervals.
885*
886* Note the circumstance that arises when the solution point lies at a
887* native pole of a projection in which the pole is represented as a
888* finite curve, for example the zenithals and conics. In such cases two
889* or more valid solutions may exist but wcsmix() only ever returns one.
890*
891* Because of its generality wcsmix() is very compute-intensive. For
892* compute-limited applications more efficient special-case solvers could
893* be written for simple projections, for example non-oblique cylindrical
894* projections.
895*
896*
897* wcsccs() - Change celestial coordinate system
898* ---------------------------------------------
899* wcsccs() changes the celestial coordinate system of a wcsprm struct. For
900* example, from equatorial to galactic coordinates.
901*
902* Parameters that define the spherical coordinate transformation, essentially
903* being three Euler angles, must be provided. Thereby wcsccs() does not need
904* prior knowledge of specific celestial coordinate systems. It also has the
905* advantage of making it completely general.
906*
907* Auxiliary members of the wcsprm struct relating to equatorial celestial
908* coordinate systems may also be changed.
909*
910* Only orthodox spherical coordinate systems are supported. That is, they
911* must be right-handed, with latitude increasing from zero at the equator to
912* +90 degrees at the pole. This precludes systems such as aziumuth and zenith
913* distance, which, however, could be handled as negative azimuth and
914* elevation.
915*
916* PLEASE NOTE: Information in the wcsprm struct relating to the original
917* coordinate system will be overwritten and therefore lost. If this is
918* undesirable, invoke wcsccs() on a copy of the struct made with wcssub().
919* The wcsprm struct is reset on return with an explicit call to wcsset().
920*
921* Given and returned:
922* wcs struct wcsprm*
923* Coordinate transformation parameters. Particular
924* "values to be given" elements of the wcsprm struct
925* are modified.
926*
927* Given:
928* lng2p1,
929* lat2p1 double Longitude and latitude in the new celestial coordinate
930* system of the pole (i.e. latitude +90) of the original
931* system [deg]. See notes 1 and 2 below.
932*
933* lng1p2 double Longitude in the original celestial coordinate system
934* of the pole (i.e. latitude +90) of the new system
935* [deg]. See note 1 below.
936*
937* clng,clat const char*
938* Longitude and latitude identifiers of the new CTYPEia
939* celestial axis codes, without trailing dashes. For
940* example, "RA" and "DEC" or "GLON" and "GLAT". Up to
941* four characters are used, longer strings need not be
942* null-terminated.
943*
944* radesys const char*
945* Used when transforming to equatorial coordinates,
946* identified by clng == "RA" and clat = "DEC". May be
947* set to the null pointer to preserve the current value.
948* Up to 71 characters are used, longer strings need not
949* be null-terminated.
950*
951* If the new coordinate system is anything other than
952* equatorial, then wcsprm::radesys will be cleared.
953*
954* equinox double Used when transforming to equatorial coordinates. May
955* be set to zero to preserve the current value.
956*
957* If the new coordinate system is not equatorial, then
958* wcsprm::equinox will be marked as undefined.
959*
960* alt const char*
961* Character code for alternate coordinate descriptions
962* (i.e. the 'a' in keyword names such as CTYPEia). This
963* is blank for the primary coordinate description, or
964* one of the 26 upper-case letters, A-Z. May be set to
965* the null pointer, or null string if no change is
966* required.
967*
968* Function return value:
969* int Status return value:
970* 0: Success.
971* 1: Null wcsprm pointer passed.
972* 12: Invalid subimage specification (no celestial
973* axes).
974*
975* Notes:
976* 1: Follows the prescription given in WCS Paper II, Sect. 2.7 for changing
977* celestial coordinates.
978*
979* The implementation takes account of indeterminacies that arise in that
980* prescription in the particular cases where one of the poles of the new
981* system is at the fiducial point, or one of them is at the native pole.
982*
983* 2: If lat2p1 == +90, i.e. where the poles of the two coordinate systems
984* coincide, then the spherical coordinate transformation becomes a simple
985* change in origin of longitude given by
986* lng2 = lng1 + (lng2p1 - lng1p2 - 180), and lat2 = lat1, where
987* (lng2,lat2) are coordinates in the new system, and (lng1,lat1) are
988* coordinates in the original system.
989*
990* Likewise, if lat2p1 == -90, then lng2 = -lng1 + (lng2p1 + lng1p2), and
991* lat2 = -lat1.
992*
993* 3: For example, if the original coordinate system is B1950 equatorial and
994* the desired new coordinate system is galactic, then
995*
996* - (lng2p1,lat2p1) are the galactic coordinates of the B1950 celestial
997* pole, defined by the IAU to be (123.0,+27.4), and lng1p2 is the B1950
998* right ascension of the galactic pole, defined as 192.25. Clearly
999* these coordinates are fixed for a particular coordinate
1000* transformation.
1001*
1002* - (clng,clat) would be 'GLON' and 'GLAT', these being the FITS standard
1003* identifiers for galactic coordinates.
1004*
1005* - Since the new coordinate system is not equatorial, wcsprm::radesys
1006* and wcsprm::equinox will be cleared.
1007*
1008* 4. The coordinates required for some common transformations (obtained from
1009* https://ned.ipac.caltech.edu/coordinate_calculator) are as follows:
1010*
1011= (123.0000,+27.4000) galactic coordinates of B1950 celestial pole,
1012= (192.2500,+27.4000) B1950 equatorial coordinates of galactic pole.
1013*
1014= (122.9319,+27.1283) galactic coordinates of J2000 celestial pole,
1015= (192.8595,+27.1283) J2000 equatorial coordinates of galactic pole.
1016*
1017= (359.6774,+89.7217) B1950 equatorial coordinates of J2000 pole,
1018= (180.3162,+89.7217) J2000 equatorial coordinates of B1950 pole.
1019*
1020= (270.0000,+66.5542) B1950 equatorial coordinates of B1950 ecliptic pole,
1021= ( 90.0000,+66.5542) B1950 ecliptic coordinates of B1950 celestial pole.
1022*
1023= (270.0000,+66.5607) J2000 equatorial coordinates of J2000 ecliptic pole,
1024= ( 90.0000,+66.5607) J2000 ecliptic coordinates of J2000 celestial pole.
1025*
1026= ( 26.7315,+15.6441) supergalactic coordinates of B1950 celestial pole,
1027= (283.1894,+15.6441) B1950 equatorial coordinates of supergalactic pole.
1028*
1029= ( 26.4505,+15.7089) supergalactic coordinates of J2000 celestial pole,
1030= (283.7542,+15.7089) J2000 equatorial coordinates of supergalactic pole.
1031*
1032*
1033* wcssptr() - Spectral axis translation
1034* -------------------------------------
1035* wcssptr() translates the spectral axis in a wcsprm struct. For example, a
1036* 'FREQ' axis may be translated into 'ZOPT-F2W' and vice versa.
1037*
1038* PLEASE NOTE: Information in the wcsprm struct relating to the original
1039* coordinate system will be overwritten and therefore lost. If this is
1040* undesirable, invoke wcssptr() on a copy of the struct made with wcssub().
1041* The wcsprm struct is reset on return with an explicit call to wcsset().
1042*
1043* Given and returned:
1044* wcs struct wcsprm*
1045* Coordinate transformation parameters.
1046*
1047* i int* Index of the spectral axis (0-relative). If given < 0
1048* it will be set to the first spectral axis identified
1049* from the ctype[] keyvalues in the wcsprm struct.
1050*
1051* ctype char[9] Desired spectral CTYPEia. Wildcarding may be used as
1052* for the ctypeS2 argument to spctrn() as described in
1053* the prologue of spc.h, i.e. if the final three
1054* characters are specified as "???", or if just the
1055* eighth character is specified as '?', the correct
1056* algorithm code will be substituted and returned.
1057*
1058* Function return value:
1059* int Status return value:
1060* 0: Success.
1061* 1: Null wcsprm pointer passed.
1062* 2: Memory allocation failed.
1063* 3: Linear transformation matrix is singular.
1064* 4: Inconsistent or unrecognized coordinate axis
1065* types.
1066* 5: Invalid parameter value.
1067* 6: Invalid coordinate transformation parameters.
1068* 7: Ill-conditioned coordinate transformation
1069* parameters.
1070* 12: Invalid subimage specification (no spectral
1071* axis).
1072*
1073* For returns > 1, a detailed error message is set in
1074* wcsprm::err if enabled, see wcserr_enable().
1075*
1076*
1077* wcslib_version() - WCSLIB version number
1078* ----------------------------------------
1079* wcslib_version() returns the WCSLIB version number.
1080*
1081* The major version number changes when the ABI changes or when the license
1082* conditions change. ABI changes typically result from a change to the
1083* contents of one of the structs. The major version number is used to
1084* distinguish between incompatible versions of the sharable library.
1085*
1086* The minor version number changes with new functionality or bug fixes that do
1087* not involve a change in the ABI.
1088*
1089* The auxiliary version number (which is often absent) signals changes to the
1090* documentation, test suite, build procedures, or any other change that does
1091* not affect the compiled library.
1092*
1093* Returned:
1094* vers[3] int[3] The broken-down version number:
1095* 0: Major version number.
1096* 1: Minor version number.
1097* 2: Auxiliary version number (zero if absent).
1098* May be given as a null pointer if not required.
1099*
1100* Function return value:
1101* char* A null-terminated, statically allocated string
1102* containing the version number in the usual form, i.e.
1103* "<major>.<minor>.<auxiliary>".
1104*
1105*
1106* wcsprm struct - Coordinate transformation parameters
1107* ----------------------------------------------------
1108* The wcsprm struct contains information required to transform world
1109* coordinates. It consists of certain members that must be set by the user
1110* ("given") and others that are set by the WCSLIB routines ("returned").
1111* While the addresses of the arrays themselves may be set by wcsinit() if it
1112* (optionally) allocates memory, their contents must be set by the user.
1113*
1114* Some parameters that are given are not actually required for transforming
1115* coordinates. These are described as "auxiliary"; the struct simply provides
1116* a place to store them, though they may be used by wcshdo() in constructing a
1117* FITS header from a wcsprm struct. Some of the returned values are supplied
1118* for informational purposes and others are for internal use only as
1119* indicated.
1120*
1121* In practice, it is expected that a WCS parser would scan the FITS header to
1122* determine the number of coordinate axes. It would then use wcsinit() to
1123* allocate memory for arrays in the wcsprm struct and set default values.
1124* Then as it reread the header and identified each WCS keyrecord it would load
1125* the value into the relevant wcsprm array element. This is essentially what
1126* wcspih() does - refer to the prologue of wcshdr.h. As the final step,
1127* wcsset() is invoked, either directly or indirectly, to set the derived
1128* members of the wcsprm struct. wcsset() strips off trailing blanks in all
1129* string members and null-fills the character array.
1130*
1131* int flag
1132* (Given and returned) This flag must be set to zero whenever any of the
1133* following wcsprm struct members are set or changed:
1134*
1135* - wcsprm::naxis (q.v., not normally set by the user),
1136* - wcsprm::crpix,
1137* - wcsprm::pc,
1138* - wcsprm::cdelt,
1139* - wcsprm::crval,
1140* - wcsprm::cunit,
1141* - wcsprm::ctype,
1142* - wcsprm::lonpole,
1143* - wcsprm::latpole,
1144* - wcsprm::restfrq,
1145* - wcsprm::restwav,
1146* - wcsprm::npv,
1147* - wcsprm::pv,
1148* - wcsprm::nps,
1149* - wcsprm::ps,
1150* - wcsprm::cd,
1151* - wcsprm::crota,
1152* - wcsprm::altlin,
1153* - wcsprm::ntab,
1154* - wcsprm::nwtb,
1155* - wcsprm::tab,
1156* - wcsprm::wtb.
1157*
1158* This signals the initialization routine, wcsset(), to recompute the
1159* returned members of the linprm, celprm, spcprm, and tabprm structs.
1160* wcsset() will reset flag to indicate that this has been done.
1161*
1162* PLEASE NOTE: flag should be set to -1 when wcsinit() is called for the
1163* first time for a particular wcsprm struct in order to initialize memory
1164* management. It must ONLY be used on the first initialization otherwise
1165* memory leaks may result.
1166*
1167* int naxis
1168* (Given or returned) Number of pixel and world coordinate elements.
1169*
1170* If wcsinit() is used to initialize the linprm struct (as would normally
1171* be the case) then it will set naxis from the value passed to it as a
1172* function argument. The user should not subsequently modify it.
1173*
1174* double *crpix
1175* (Given) Address of the first element of an array of double containing
1176* the coordinate reference pixel, CRPIXja.
1177*
1178* double *pc
1179* (Given) Address of the first element of the PCi_ja (pixel coordinate)
1180* transformation matrix. The expected order is
1181*
1182= struct wcsprm wcs;
1183= wcs.pc = {PC1_1, PC1_2, PC2_1, PC2_2};
1184*
1185* This may be constructed conveniently from a 2-D array via
1186*
1187= double m[2][2] = {{PC1_1, PC1_2},
1188= {PC2_1, PC2_2}};
1189*
1190* which is equivalent to
1191*
1192= double m[2][2];
1193= m[0][0] = PC1_1;
1194= m[0][1] = PC1_2;
1195= m[1][0] = PC2_1;
1196= m[1][1] = PC2_2;
1197*
1198* The storage order for this 2-D array is the same as for the 1-D array,
1199* whence
1200*
1201= wcs.pc = *m;
1202*
1203* would be legitimate.
1204*
1205* double *cdelt
1206* (Given) Address of the first element of an array of double containing
1207* the coordinate increments, CDELTia.
1208*
1209* double *crval
1210* (Given) Address of the first element of an array of double containing
1211* the coordinate reference values, CRVALia.
1212*
1213* char (*cunit)[72]
1214* (Given) Address of the first element of an array of char[72] containing
1215* the CUNITia keyvalues which define the units of measurement of the
1216* CRVALia, CDELTia, and CDi_ja keywords.
1217*
1218* As CUNITia is an optional header keyword, cunit[][72] may be left blank
1219* but otherwise is expected to contain a standard units specification as
1220* defined by WCS Paper I. Utility function wcsutrn(), described in
1221* wcsunits.h, is available to translate commonly used non-standard units
1222* specifications but this must be done as a separate step before invoking
1223* wcsset().
1224*
1225* For celestial axes, if cunit[][72] is not blank, wcsset() uses
1226* wcsunits() to parse it and scale cdelt[], crval[], and cd[][*] to
1227* degrees. It then resets cunit[][72] to "deg".
1228*
1229* For spectral axes, if cunit[][72] is not blank, wcsset() uses wcsunits()
1230* to parse it and scale cdelt[], crval[], and cd[][*] to SI units. It
1231* then resets cunit[][72] accordingly.
1232*
1233* wcsset() ignores cunit[][72] for other coordinate types; cunit[][72] may
1234* be used to label coordinate values.
1235*
1236* These variables accomodate the longest allowed string-valued FITS
1237* keyword, being limited to 68 characters, plus the null-terminating
1238* character.
1239*
1240* char (*ctype)[72]
1241* (Given) Address of the first element of an array of char[72] containing
1242* the coordinate axis types, CTYPEia.
1243*
1244* The ctype[][72] keyword values must be in upper case and there must be
1245* zero or one pair of matched celestial axis types, and zero or one
1246* spectral axis. The ctype[][72] strings should be padded with blanks on
1247* the right and null-terminated so that they are at least eight characters
1248* in length.
1249*
1250* These variables accomodate the longest allowed string-valued FITS
1251* keyword, being limited to 68 characters, plus the null-terminating
1252* character.
1253*
1254* double lonpole
1255* (Given and returned) The native longitude of the celestial pole, phi_p,
1256* given by LONPOLEa [deg] or by PVi_2a [deg] attached to the longitude
1257* axis which takes precedence if defined, and ...
1258* double latpole
1259* (Given and returned) ... the native latitude of the celestial pole,
1260* theta_p, given by LATPOLEa [deg] or by PVi_3a [deg] attached to the
1261* longitude axis which takes precedence if defined.
1262*
1263* lonpole and latpole may be left to default to values set by wcsinit()
1264* (see celprm::ref), but in any case they will be reset by wcsset() to
1265* the values actually used. Note therefore that if the wcsprm struct is
1266* reused without resetting them, whether directly or via wcsinit(), they
1267* will no longer have their default values.
1268*
1269* double restfrq
1270* (Given) The rest frequency [Hz], and/or ...
1271* double restwav
1272* (Given) ... the rest wavelength in vacuo [m], only one of which need be
1273* given, the other should be set to zero.
1274*
1275* int npv
1276* (Given) The number of entries in the wcsprm::pv[] array.
1277*
1278* int npvmax
1279* (Given or returned) The length of the wcsprm::pv[] array.
1280*
1281* npvmax will be set by wcsinit() if it allocates memory for wcsprm::pv[],
1282* otherwise it must be set by the user. See also wcsnpv().
1283*
1284* struct pvcard *pv
1285* (Given) Address of the first element of an array of length npvmax of
1286* pvcard structs.
1287*
1288* As a FITS header parser encounters each PVi_ma keyword it should load it
1289* into a pvcard struct in the array and increment npv. wcsset()
1290* interprets these as required.
1291*
1292* Note that, if they were not given, wcsset() resets the entries for
1293* PVi_1a, PVi_2a, PVi_3a, and PVi_4a for longitude axis i to match
1294* phi_0 and theta_0 (the native longitude and latitude of the reference
1295* point), LONPOLEa and LATPOLEa respectively.
1296*
1297* int nps
1298* (Given) The number of entries in the wcsprm::ps[] array.
1299*
1300* int npsmax
1301* (Given or returned) The length of the wcsprm::ps[] array.
1302*
1303* npsmax will be set by wcsinit() if it allocates memory for wcsprm::ps[],
1304* otherwise it must be set by the user. See also wcsnps().
1305*
1306* struct pscard *ps
1307* (Given) Address of the first element of an array of length npsmax of
1308* pscard structs.
1309*
1310* As a FITS header parser encounters each PSi_ma keyword it should load it
1311* into a pscard struct in the array and increment nps. wcsset()
1312* interprets these as required (currently no PSi_ma keyvalues are
1313* recognized).
1314*
1315* double *cd
1316* (Given) For historical compatibility, the wcsprm struct supports two
1317* alternate specifications of the linear transformation matrix, those
1318* associated with the CDi_ja keywords, and ...
1319* double *crota
1320* (Given) ... those associated with the CROTAi keywords. Although these
1321* may not formally co-exist with PCi_ja, the approach taken here is simply
1322* to ignore them if given in conjunction with PCi_ja.
1323*
1324* int altlin
1325* (Given) altlin is a bit flag that denotes which of the PCi_ja, CDi_ja
1326* and CROTAi keywords are present in the header:
1327*
1328* - Bit 0: PCi_ja is present.
1329*
1330* - Bit 1: CDi_ja is present.
1331*
1332* Matrix elements in the IRAF convention are equivalent to the product
1333* CDi_ja = CDELTia * PCi_ja, but the defaults differ from that of the
1334* PCi_ja matrix. If one or more CDi_ja keywords are present then all
1335* unspecified CDi_ja default to zero. If no CDi_ja (or CROTAi) keywords
1336* are present, then the header is assumed to be in PCi_ja form whether
1337* or not any PCi_ja keywords are present since this results in an
1338* interpretation of CDELTia consistent with the original FITS
1339* specification.
1340*
1341* While CDi_ja may not formally co-exist with PCi_ja, it may co-exist
1342* with CDELTia and CROTAi which are to be ignored.
1343*
1344* - Bit 2: CROTAi is present.
1345*
1346* In the AIPS convention, CROTAi may only be associated with the
1347* latitude axis of a celestial axis pair. It specifies a rotation in
1348* the image plane that is applied AFTER the CDELTia; any other CROTAi
1349* keywords are ignored.
1350*
1351* CROTAi may not formally co-exist with PCi_ja.
1352*
1353* CROTAi and CDELTia may formally co-exist with CDi_ja but if so are to
1354* be ignored.
1355*
1356* - Bit 3: PCi_ja + CDELTia was derived from CDi_ja by wcspcx().
1357*
1358* This bit is set by wcspcx() when it derives PCi_ja and CDELTia from
1359* CDi_ja via an orthonormal decomposition. In particular, it signals
1360* wcsset() not to replace PCi_ja by a copy of CDi_ja with CDELTia set
1361* to unity.
1362*
1363* CDi_ja and CROTAi keywords, if found, are to be stored in the wcsprm::cd
1364* and wcsprm::crota arrays which are dimensioned similarly to wcsprm::pc
1365* and wcsprm::cdelt. FITS header parsers should use the following
1366* procedure:
1367*
1368* - Whenever a PCi_ja keyword is encountered: altlin |= 1;
1369*
1370* - Whenever a CDi_ja keyword is encountered: altlin |= 2;
1371*
1372* - Whenever a CROTAi keyword is encountered: altlin |= 4;
1373*
1374* If none of these bits are set the PCi_ja representation results, i.e.
1375* wcsprm::pc and wcsprm::cdelt will be used as given.
1376*
1377* These alternate specifications of the linear transformation matrix are
1378* translated immediately to PCi_ja by wcsset() and are invisible to the
1379* lower-level WCSLIB routines. In particular, unless bit 3 is also set,
1380* wcsset() resets wcsprm::cdelt to unity if CDi_ja is present (and no
1381* PCi_ja).
1382*
1383* If CROTAi are present but none is associated with the latitude axis
1384* (and no PCi_ja or CDi_ja), then wcsset() reverts to a unity PCi_ja
1385* matrix.
1386*
1387* int velref
1388* (Given) AIPS velocity code VELREF, refer to spcaips().
1389*
1390* It is not necessary to reset the wcsprm struct (via wcsset()) when
1391* wcsprm::velref is changed.
1392*
1393* char alt[4]
1394* (Given, auxiliary) Character code for alternate coordinate descriptions
1395* (i.e. the 'a' in keyword names such as CTYPEia). This is blank for the
1396* primary coordinate description, or one of the 26 upper-case letters,
1397* A-Z.
1398*
1399* An array of four characters is provided for alignment purposes, only the
1400* first is used.
1401*
1402* It is not necessary to reset the wcsprm struct (via wcsset()) when
1403* wcsprm::alt is changed.
1404*
1405* int colnum
1406* (Given, auxiliary) Where the coordinate representation is associated
1407* with an image-array column in a FITS binary table, this variable may be
1408* used to record the relevant column number.
1409*
1410* It should be set to zero for an image header or pixel list.
1411*
1412* It is not necessary to reset the wcsprm struct (via wcsset()) when
1413* wcsprm::colnum is changed.
1414*
1415* int *colax
1416* (Given, auxiliary) Address of the first element of an array of int
1417* recording the column numbers for each axis in a pixel list.
1418*
1419* The array elements should be set to zero for an image header or image
1420* array in a binary table.
1421*
1422* It is not necessary to reset the wcsprm struct (via wcsset()) when
1423* wcsprm::colax is changed.
1424*
1425* char (*cname)[72]
1426* (Given, auxiliary) The address of the first element of an array of
1427* char[72] containing the coordinate axis names, CNAMEia.
1428*
1429* These variables accomodate the longest allowed string-valued FITS
1430* keyword, being limited to 68 characters, plus the null-terminating
1431* character.
1432*
1433* It is not necessary to reset the wcsprm struct (via wcsset()) when
1434* wcsprm::cname is changed.
1435*
1436* double *crder
1437* (Given, auxiliary) Address of the first element of an array of double
1438* recording the random error in the coordinate value, CRDERia.
1439*
1440* It is not necessary to reset the wcsprm struct (via wcsset()) when
1441* wcsprm::crder is changed.
1442*
1443* double *csyer
1444* (Given, auxiliary) Address of the first element of an array of double
1445* recording the systematic error in the coordinate value, CSYERia.
1446*
1447* It is not necessary to reset the wcsprm struct (via wcsset()) when
1448* wcsprm::csyer is changed.
1449*
1450* double *czphs
1451* (Given, auxiliary) Address of the first element of an array of double
1452* recording the time at the zero point of a phase axis, CZPHSia.
1453*
1454* It is not necessary to reset the wcsprm struct (via wcsset()) when
1455* wcsprm::czphs is changed.
1456*
1457* double *cperi
1458* (Given, auxiliary) Address of the first element of an array of double
1459* recording the period of a phase axis, CPERIia.
1460*
1461* It is not necessary to reset the wcsprm struct (via wcsset()) when
1462* wcsprm::cperi is changed.
1463*
1464* char wcsname[72]
1465* (Given, auxiliary) The name given to the coordinate representation,
1466* WCSNAMEa. This variable accomodates the longest allowed string-valued
1467* FITS keyword, being limited to 68 characters, plus the null-terminating
1468* character.
1469*
1470* It is not necessary to reset the wcsprm struct (via wcsset()) when
1471* wcsprm::wcsname is changed.
1472*
1473* char timesys[72]
1474* (Given, auxiliary) TIMESYS keyvalue, being the time scale (UTC, TAI,
1475* etc.) in which all other time-related auxiliary header values are
1476* recorded. Also defines the time scale for an image axis with CTYPEia
1477* set to 'TIME'.
1478*
1479* It is not necessary to reset the wcsprm struct (via wcsset()) when
1480* wcsprm::timesys is changed.
1481*
1482* char trefpos[72]
1483* (Given, auxiliary) TREFPOS keyvalue, being the location in space where
1484* the recorded time is valid.
1485*
1486* It is not necessary to reset the wcsprm struct (via wcsset()) when
1487* wcsprm::trefpos is changed.
1488*
1489* char trefdir[72]
1490* (Given, auxiliary) TREFDIR keyvalue, being the reference direction used
1491* in calculating a pathlength delay.
1492*
1493* It is not necessary to reset the wcsprm struct (via wcsset()) when
1494* wcsprm::trefdir is changed.
1495*
1496* char plephem[72]
1497* (Given, auxiliary) PLEPHEM keyvalue, being the Solar System ephemeris
1498* used for calculating a pathlength delay.
1499*
1500* It is not necessary to reset the wcsprm struct (via wcsset()) when
1501* wcsprm::plephem is changed.
1502*
1503* char timeunit[72]
1504* (Given, auxiliary) TIMEUNIT keyvalue, being the time units in which
1505* the following header values are expressed: TSTART, TSTOP, TIMEOFFS,
1506* TIMSYER, TIMRDER, TIMEDEL. It also provides the default value for
1507* CUNITia for time axes.
1508*
1509* It is not necessary to reset the wcsprm struct (via wcsset()) when
1510* wcsprm::timeunit is changed.
1511*
1512* char dateref[72]
1513* (Given, auxiliary) DATEREF keyvalue, being the date of a reference epoch
1514* relative to which other time measurements refer.
1515*
1516* It is not necessary to reset the wcsprm struct (via wcsset()) when
1517* wcsprm::dateref is changed.
1518*
1519* double mjdref[2]
1520* (Given, auxiliary) MJDREF keyvalue, equivalent to DATEREF expressed as
1521* a Modified Julian Date (MJD = JD - 2400000.5). The value is given as
1522* the sum of the two-element vector, allowing increased precision.
1523*
1524* It is not necessary to reset the wcsprm struct (via wcsset()) when
1525* wcsprm::mjdref is changed.
1526*
1527* double timeoffs
1528* (Given, auxiliary) TIMEOFFS keyvalue, being a time offset, which may be
1529* used, for example, to provide a uniform clock correction for times
1530* referenced to DATEREF.
1531*
1532* It is not necessary to reset the wcsprm struct (via wcsset()) when
1533* wcsprm::timeoffs is changed.
1534*
1535* char dateobs[72]
1536* (Given, auxiliary) DATE-OBS keyvalue, being the date at the start of the
1537* observation unless otherwise explained in the DATE-OBS keycomment, in
1538* ISO format, yyyy-mm-ddThh:mm:ss.
1539*
1540* It is not necessary to reset the wcsprm struct (via wcsset()) when
1541* wcsprm::dateobs is changed.
1542*
1543* char datebeg[72]
1544* (Given, auxiliary) DATE-BEG keyvalue, being the date at the start of the
1545* observation in ISO format, yyyy-mm-ddThh:mm:ss.
1546*
1547* It is not necessary to reset the wcsprm struct (via wcsset()) when
1548* wcsprm::datebeg is changed.
1549*
1550* char dateavg[72]
1551* (Given, auxiliary) DATE-AVG keyvalue, being the date at a representative
1552* mid-point of the observation in ISO format, yyyy-mm-ddThh:mm:ss.
1553*
1554* It is not necessary to reset the wcsprm struct (via wcsset()) when
1555* wcsprm::dateavg is changed.
1556*
1557* char dateend[72]
1558* (Given, auxiliary) DATE-END keyvalue, baing the date at the end of the
1559* observation in ISO format, yyyy-mm-ddThh:mm:ss.
1560*
1561* It is not necessary to reset the wcsprm struct (via wcsset()) when
1562* wcsprm::dateend is changed.
1563*
1564* double mjdobs
1565* (Given, auxiliary) MJD-OBS keyvalue, equivalent to DATE-OBS expressed
1566* as a Modified Julian Date (MJD = JD - 2400000.5).
1567*
1568* It is not necessary to reset the wcsprm struct (via wcsset()) when
1569* wcsprm::mjdobs is changed.
1570*
1571* double mjdbeg
1572* (Given, auxiliary) MJD-BEG keyvalue, equivalent to DATE-BEG expressed
1573* as a Modified Julian Date (MJD = JD - 2400000.5).
1574*
1575* It is not necessary to reset the wcsprm struct (via wcsset()) when
1576* wcsprm::mjdbeg is changed.
1577*
1578* double mjdavg
1579* (Given, auxiliary) MJD-AVG keyvalue, equivalent to DATE-AVG expressed
1580* as a Modified Julian Date (MJD = JD - 2400000.5).
1581*
1582* It is not necessary to reset the wcsprm struct (via wcsset()) when
1583* wcsprm::mjdavg is changed.
1584*
1585* double mjdend
1586* (Given, auxiliary) MJD-END keyvalue, equivalent to DATE-END expressed
1587* as a Modified Julian Date (MJD = JD - 2400000.5).
1588*
1589* It is not necessary to reset the wcsprm struct (via wcsset()) when
1590* wcsprm::mjdend is changed.
1591*
1592* double jepoch
1593* (Given, auxiliary) JEPOCH keyvalue, equivalent to DATE-OBS expressed
1594* as a Julian epoch.
1595*
1596* It is not necessary to reset the wcsprm struct (via wcsset()) when
1597* wcsprm::jepoch is changed.
1598*
1599* double bepoch
1600* (Given, auxiliary) BEPOCH keyvalue, equivalent to DATE-OBS expressed
1601* as a Besselian epoch
1602*
1603* It is not necessary to reset the wcsprm struct (via wcsset()) when
1604* wcsprm::bepoch is changed.
1605*
1606* double tstart
1607* (Given, auxiliary) TSTART keyvalue, equivalent to DATE-BEG expressed
1608* as a time in units of TIMEUNIT relative to DATEREF+TIMEOFFS.
1609*
1610* It is not necessary to reset the wcsprm struct (via wcsset()) when
1611* wcsprm::tstart is changed.
1612*
1613* double tstop
1614* (Given, auxiliary) TSTOP keyvalue, equivalent to DATE-END expressed
1615* as a time in units of TIMEUNIT relative to DATEREF+TIMEOFFS.
1616*
1617* It is not necessary to reset the wcsprm struct (via wcsset()) when
1618* wcsprm::tstop is changed.
1619*
1620* double xposure
1621* (Given, auxiliary) XPOSURE keyvalue, being the effective exposure time
1622* in units of TIMEUNIT.
1623*
1624* It is not necessary to reset the wcsprm struct (via wcsset()) when
1625* wcsprm::xposure is changed.
1626*
1627* double telapse
1628* (Given, auxiliary) TELAPSE keyvalue, equivalent to the elapsed time
1629* between DATE-BEG and DATE-END, in units of TIMEUNIT.
1630*
1631* It is not necessary to reset the wcsprm struct (via wcsset()) when
1632* wcsprm::telapse is changed.
1633*
1634* double timsyer
1635* (Given, auxiliary) TIMSYER keyvalue, being the absolute error of the
1636* time values, in units of TIMEUNIT.
1637*
1638* It is not necessary to reset the wcsprm struct (via wcsset()) when
1639* wcsprm::timsyer is changed.
1640*
1641* double timrder
1642* (Given, auxiliary) TIMRDER keyvalue, being the accuracy of time stamps
1643* relative to each other, in units of TIMEUNIT.
1644*
1645* It is not necessary to reset the wcsprm struct (via wcsset()) when
1646* wcsprm::timrder is changed.
1647*
1648* double timedel
1649* (Given, auxiliary) TIMEDEL keyvalue, being the resolution of the time
1650* stamps.
1651*
1652* It is not necessary to reset the wcsprm struct (via wcsset()) when
1653* wcsprm::timedel is changed.
1654*
1655* double timepixr
1656* (Given, auxiliary) TIMEPIXR keyvalue, being the relative position of the
1657* time stamps in binned time intervals, a value between 0.0 and 1.0.
1658*
1659* It is not necessary to reset the wcsprm struct (via wcsset()) when
1660* wcsprm::timepixr is changed.
1661*
1662* double obsgeo[6]
1663* (Given, auxiliary) Location of the observer in a standard terrestrial
1664* reference frame. The first three give ITRS Cartesian coordinates
1665* OBSGEO-X [m], OBSGEO-Y [m], OBSGEO-Z [m], and the second three give
1666* OBSGEO-L [deg], OBSGEO-B [deg], OBSGEO-H [m], which are related through
1667* a standard transformation.
1668*
1669* It is not necessary to reset the wcsprm struct (via wcsset()) when
1670* wcsprm::obsgeo is changed.
1671*
1672* char obsorbit[72]
1673* (Given, auxiliary) OBSORBIT keyvalue, being the URI, URL, or name of an
1674* orbit ephemeris file giving spacecraft coordinates relating to TREFPOS.
1675*
1676* It is not necessary to reset the wcsprm struct (via wcsset()) when
1677* wcsprm::obsorbit is changed.
1678*
1679* char radesys[72]
1680* (Given, auxiliary) The equatorial or ecliptic coordinate system type,
1681* RADESYSa.
1682*
1683* It is not necessary to reset the wcsprm struct (via wcsset()) when
1684* wcsprm::radesys is changed.
1685*
1686* double equinox
1687* (Given, auxiliary) The equinox associated with dynamical equatorial or
1688* ecliptic coordinate systems, EQUINOXa (or EPOCH in older headers). Not
1689* applicable to ICRS equatorial or ecliptic coordinates.
1690*
1691* It is not necessary to reset the wcsprm struct (via wcsset()) when
1692* wcsprm::equinox is changed.
1693*
1694* char specsys[72]
1695* (Given, auxiliary) Spectral reference frame (standard of rest),
1696* SPECSYSa.
1697*
1698* It is not necessary to reset the wcsprm struct (via wcsset()) when
1699* wcsprm::specsys is changed.
1700*
1701* char ssysobs[72]
1702* (Given, auxiliary) The spectral reference frame in which there is no
1703* differential variation in the spectral coordinate across the
1704* field-of-view, SSYSOBSa.
1705*
1706* It is not necessary to reset the wcsprm struct (via wcsset()) when
1707* wcsprm::ssysobs is changed.
1708*
1709* double velosys
1710* (Given, auxiliary) The relative radial velocity [m/s] between the
1711* observer and the selected standard of rest in the direction of the
1712* celestial reference coordinate, VELOSYSa.
1713*
1714* It is not necessary to reset the wcsprm struct (via wcsset()) when
1715* wcsprm::velosys is changed.
1716*
1717* double zsource
1718* (Given, auxiliary) The redshift, ZSOURCEa, of the source.
1719*
1720* It is not necessary to reset the wcsprm struct (via wcsset()) when
1721* wcsprm::zsource is changed.
1722*
1723* char ssyssrc[72]
1724* (Given, auxiliary) The spectral reference frame (standard of rest),
1725* SSYSSRCa, in which wcsprm::zsource was measured.
1726*
1727* It is not necessary to reset the wcsprm struct (via wcsset()) when
1728* wcsprm::ssyssrc is changed.
1729*
1730* double velangl
1731* (Given, auxiliary) The angle [deg] that should be used to decompose an
1732* observed velocity into radial and transverse components.
1733*
1734* It is not necessary to reset the wcsprm struct (via wcsset()) when
1735* wcsprm::velangl is changed.
1736*
1737* struct auxprm *aux
1738* (Given, auxiliary) This struct holds auxiliary coordinate system
1739* information of a specialist nature. While these parameters may be
1740* widely recognized within particular fields of astronomy, they differ
1741* from the above auxiliary parameters in not being defined by any of the
1742* FITS WCS standards. Collecting them together in a separate struct that
1743* is allocated only when required helps to control bloat in the size of
1744* the wcsprm struct.
1745*
1746* int ntab
1747* (Given) See wcsprm::tab.
1748*
1749* int nwtb
1750* (Given) See wcsprm::wtb.
1751*
1752* struct tabprm *tab
1753* (Given) Address of the first element of an array of ntab tabprm structs
1754* for which memory has been allocated. These are used to store tabular
1755* transformation parameters.
1756*
1757* Although technically wcsprm::ntab and tab are "given", they will
1758* normally be set by invoking wcstab(), whether directly or indirectly.
1759*
1760* The tabprm structs contain some members that must be supplied and others
1761* that are derived. The information to be supplied comes primarily from
1762* arrays stored in one or more FITS binary table extensions. These
1763* arrays, referred to here as "wcstab arrays", are themselves located by
1764* parameters stored in the FITS image header.
1765*
1766* struct wtbarr *wtb
1767* (Given) Address of the first element of an array of nwtb wtbarr structs
1768* for which memory has been allocated. These are used in extracting
1769* wcstab arrays from a FITS binary table.
1770*
1771* Although technically wcsprm::nwtb and wtb are "given", they will
1772* normally be set by invoking wcstab(), whether directly or indirectly.
1773*
1774* char lngtyp[8]
1775* (Returned) Four-character WCS celestial longitude and ...
1776* char lattyp[8]
1777* (Returned) ... latitude axis types. e.g. "RA", "DEC", "GLON", "GLAT",
1778* etc. extracted from 'RA--', 'DEC-', 'GLON', 'GLAT', etc. in the first
1779* four characters of CTYPEia but with trailing dashes removed. (Declared
1780* as char[8] for alignment reasons.)
1781*
1782* int lng
1783* (Returned) Index for the longitude coordinate, and ...
1784* int lat
1785* (Returned) ... index for the latitude coordinate, and ...
1786* int spec
1787* (Returned) ... index for the spectral coordinate in the imgcrd[][] and
1788* world[][] arrays in the API of wcsp2s(), wcss2p() and wcsmix().
1789*
1790* These may also serve as indices into the pixcrd[][] array provided that
1791* the PCi_ja matrix does not transpose axes.
1792*
1793* int cubeface
1794* (Returned) Index into the pixcrd[][] array for the CUBEFACE axis. This
1795* is used for quadcube projections where the cube faces are stored on a
1796* separate axis (see wcs.h).
1797*
1798* int *types
1799* (Returned) Address of the first element of an array of int containing a
1800* four-digit type code for each axis.
1801*
1802* - First digit (i.e. 1000s):
1803* - 0: Non-specific coordinate type.
1804* - 1: Stokes coordinate.
1805* - 2: Celestial coordinate (including CUBEFACE).
1806* - 3: Spectral coordinate.
1807* - 4: Time coordinate.
1808*
1809* - Second digit (i.e. 100s):
1810* - 0: Linear axis.
1811* - 1: Quantized axis (STOKES, CUBEFACE).
1812* - 2: Non-linear celestial axis.
1813* - 3: Non-linear spectral axis.
1814* - 4: Logarithmic axis.
1815* - 5: Tabular axis.
1816*
1817* - Third digit (i.e. 10s):
1818* - 0: Group number, e.g. lookup table number, being an index into the
1819* tabprm array (see above).
1820*
1821* - The fourth digit is used as a qualifier depending on the axis type.
1822*
1823* - For celestial axes:
1824* - 0: Longitude coordinate.
1825* - 1: Latitude coordinate.
1826* - 2: CUBEFACE number.
1827*
1828* - For lookup tables: the axis number in a multidimensional table.
1829*
1830* CTYPEia in "4-3" form with unrecognized algorithm code will have its
1831* type set to -1 and generate an error.
1832*
1833* struct linprm lin
1834* (Returned) Linear transformation parameters (usage is described in the
1835* prologue to lin.h).
1836*
1837* struct celprm cel
1838* (Returned) Celestial transformation parameters (usage is described in
1839* the prologue to cel.h).
1840*
1841* struct spcprm spc
1842* (Returned) Spectral transformation parameters (usage is described in the
1843* prologue to spc.h).
1844*
1845* struct wcserr *err
1846* (Returned) If enabled, when an error status is returned, this struct
1847* contains detailed information about the error, see wcserr_enable().
1848*
1849* int m_flag
1850* (For internal use only.)
1851* int m_naxis
1852* (For internal use only.)
1853* double *m_crpix
1854* (For internal use only.)
1855* double *m_pc
1856* (For internal use only.)
1857* double *m_cdelt
1858* (For internal use only.)
1859* double *m_crval
1860* (For internal use only.)
1861* char (*m_cunit)[72]
1862* (For internal use only.)
1863* char (*m_ctype)[72]
1864* (For internal use only.)
1865* struct pvcard *m_pv
1866* (For internal use only.)
1867* struct pscard *m_ps
1868* (For internal use only.)
1869* double *m_cd
1870* (For internal use only.)
1871* double *m_crota
1872* (For internal use only.)
1873* int *m_colax
1874* (For internal use only.)
1875* char (*m_cname)[72]
1876* (For internal use only.)
1877* double *m_crder
1878* (For internal use only.)
1879* double *m_csyer
1880* (For internal use only.)
1881* double *m_czphs
1882* (For internal use only.)
1883* double *m_cperi
1884* (For internal use only.)
1885* struct tabprm *m_tab
1886* (For internal use only.)
1887* struct wtbarr *m_wtb
1888* (For internal use only.)
1889*
1890*
1891* pvcard struct - Store for PVi_ma keyrecords
1892* -------------------------------------------
1893* The pvcard struct is used to pass the parsed contents of PVi_ma keyrecords
1894* to wcsset() via the wcsprm struct.
1895*
1896* All members of this struct are to be set by the user.
1897*
1898* int i
1899* (Given) Axis number (1-relative), as in the FITS PVi_ma keyword. If
1900* i == 0, wcsset() will replace it with the latitude axis number.
1901*
1902* int m
1903* (Given) Parameter number (non-negative), as in the FITS PVi_ma keyword.
1904*
1905* double value
1906* (Given) Parameter value.
1907*
1908*
1909* pscard struct - Store for PSi_ma keyrecords
1910* -------------------------------------------
1911* The pscard struct is used to pass the parsed contents of PSi_ma keyrecords
1912* to wcsset() via the wcsprm struct.
1913*
1914* All members of this struct are to be set by the user.
1915*
1916* int i
1917* (Given) Axis number (1-relative), as in the FITS PSi_ma keyword.
1918*
1919* int m
1920* (Given) Parameter number (non-negative), as in the FITS PSi_ma keyword.
1921*
1922* char value[72]
1923* (Given) Parameter value.
1924*
1925*
1926* auxprm struct - Additional auxiliary parameters
1927* -----------------------------------------------
1928* The auxprm struct holds auxiliary coordinate system information of a
1929* specialist nature. It is anticipated that this struct will expand in future
1930* to accomodate additional parameters.
1931*
1932* All members of this struct are to be set by the user.
1933*
1934* double rsun_ref
1935* (Given, auxiliary) Reference radius of the Sun used in coordinate
1936* calculations (m).
1937*
1938* double dsun_obs
1939* (Given, auxiliary) Distance between the centre of the Sun and the
1940* observer (m).
1941*
1942* double crln_obs
1943* (Given, auxiliary) Carrington heliographic longitude of the observer
1944* (deg).
1945*
1946* double hgln_obs
1947* (Given, auxiliary) Stonyhurst heliographic longitude of the observer
1948* (deg).
1949*
1950* double hglt_obs
1951* (Given, auxiliary) Heliographic latitude (Carrington or Stonyhurst) of
1952* the observer (deg).
1953*
1954*
1955* Global variable: const char *wcs_errmsg[] - Status return messages
1956* ------------------------------------------------------------------
1957* Error messages to match the status value returned from each function.
1958*
1959*===========================================================================*/
1960
1961#ifndef WCSLIB_WCS
1962#define WCSLIB_WCS
1963
1964#include "lin.h"
1965#include "cel.h"
1966#include "spc.h"
1967
1968#ifdef __cplusplus
1969extern "C" {
1970#define wtbarr wtbarr_s // See prologue of wtbarr.h.
1971#endif
1972
1973#define WCSSUB_LONGITUDE 0x1001
1974#define WCSSUB_LATITUDE 0x1002
1975#define WCSSUB_CUBEFACE 0x1004
1976#define WCSSUB_CELESTIAL 0x1007
1977#define WCSSUB_SPECTRAL 0x1008
1978#define WCSSUB_STOKES 0x1010
1979#define WCSSUB_TIME 0x1020
1980
1981
1982#define WCSCOMPARE_ANCILLARY 0x0001
1983#define WCSCOMPARE_TILING 0x0002
1984#define WCSCOMPARE_CRPIX 0x0004
1985
1986
1987extern const char *wcs_errmsg[];
1988
1989 enum wcs_errmsg_enum {
1990 WCSERR_SUCCESS = 0, // Success.
1991 WCSERR_NULL_POINTER = 1, // Null wcsprm pointer passed.
1992 WCSERR_MEMORY = 2, // Memory allocation failed.
1993 WCSERR_SINGULAR_MTX = 3, // Linear transformation matrix is singular.
1994 WCSERR_BAD_CTYPE = 4, // Inconsistent or unrecognized coordinate
1995 // axis type.
1996 WCSERR_BAD_PARAM = 5, // Invalid parameter value.
1997 WCSERR_BAD_COORD_TRANS = 6, // Unrecognized coordinate transformation
1998 // parameter.
1999 WCSERR_ILL_COORD_TRANS = 7, // Ill-conditioned coordinate transformation
2000 // parameter.
2001 WCSERR_BAD_PIX = 8, // One or more of the pixel coordinates were
2002 // invalid.
2003 WCSERR_BAD_WORLD = 9, // One or more of the world coordinates were
2004 // invalid.
2005 WCSERR_BAD_WORLD_COORD = 10, // Invalid world coordinate.
2006 WCSERR_NO_SOLUTION = 11, // No solution found in the specified
2007 // interval.
2008 WCSERR_BAD_SUBIMAGE = 12, // Invalid subimage specification.
2009 WCSERR_NON_SEPARABLE = 13, // Non-separable subimage coordinate system.
2010 WCSERR_UNSET = 14 // wcsprm struct is unset.
2011};
2012
2013
2014// Struct used for storing PVi_ma keywords.
2015 struct pvcard {
2016 int i; // Axis number, as in PVi_ma (1-relative).
2017 int m; // Parameter number, ditto (0-relative).
2018 double value; // Parameter value.
2019};
2020
2021// Size of the pvcard struct in int units, used by the Fortran wrappers.
2022#define PVLEN (sizeof(struct pvcard)/sizeof(int))
2023
2024// Struct used for storing PSi_ma keywords.
2025 struct pscard {
2026 int i; // Axis number, as in PSi_ma (1-relative).
2027 int m; // Parameter number, ditto (0-relative).
2028 char value[72]; // Parameter value.
2029};
2030
2031// Size of the pscard struct in int units, used by the Fortran wrappers.
2032#define PSLEN (sizeof(struct pscard)/sizeof(int))
2033
2034// Struct used to hold additional auxiliary parameters.
2035 struct auxprm {
2036 double rsun_ref; // Solar radius.
2037 double dsun_obs; // Distance from Sun centre to observer.
2038 double crln_obs; // Carrington heliographic lng of observer.
2039 double hgln_obs; // Stonyhurst heliographic lng of observer.
2040 double hglt_obs; // Heliographic latitude of observer.
2041};
2042
2043// Size of the auxprm struct in int units, used by the Fortran wrappers.
2044#define AUXLEN (sizeof(struct auxprm)/sizeof(int))
2045
2046
2047 struct wcsprm {
2048 // Initialization flag (see the prologue above).
2049 //--------------------------------------------------------------------------
2050 int flag; // Set to zero to force initialization.
2051
2052 // FITS header keyvalues to be provided (see the prologue above).
2053 //--------------------------------------------------------------------------
2054 int naxis; // Number of axes (pixel and coordinate).
2055 double *crpix; // CRPIXja keyvalues for each pixel axis.
2056 double *pc; // PCi_ja linear transformation matrix.
2057 double *cdelt; // CDELTia keyvalues for each coord axis.
2058 double *crval; // CRVALia keyvalues for each coord axis.
2059
2060 char (*cunit)[72]; // CUNITia keyvalues for each coord axis.
2061 char (*ctype)[72]; // CTYPEia keyvalues for each coord axis.
2062
2063 double lonpole; // LONPOLEa keyvalue.
2064 double latpole; // LATPOLEa keyvalue.
2065
2066 double restfrq; // RESTFRQa keyvalue.
2067 double restwav; // RESTWAVa keyvalue.
2068
2069 int npv; // Number of PVi_ma keywords, and the
2070 int npvmax; // number for which space was allocated.
2071 struct pvcard *pv; // PVi_ma keywords for each i and m.
2072
2073 int nps; // Number of PSi_ma keywords, and the
2074 int npsmax; // number for which space was allocated.
2075 struct pscard *ps; // PSi_ma keywords for each i and m.
2076
2077 // Alternative header keyvalues (see the prologue above).
2078 //--------------------------------------------------------------------------
2079 double *cd; // CDi_ja linear transformation matrix.
2080 double *crota; // CROTAi keyvalues for each coord axis.
2081 int altlin; // Alternative representations
2082 // Bit 0: PCi_ja is present,
2083 // Bit 1: CDi_ja is present,
2084 // Bit 2: CROTAi is present.
2085 int velref; // AIPS velocity code, VELREF.
2086
2087 // Auxiliary coordinate system information of a general nature. Not
2088 // used by WCSLIB. Refer to the prologue comments above for a brief
2089 // explanation of these values.
2090 char alt[4];
2091 int colnum;
2092 int *colax;
2093 // Auxiliary coordinate axis information.
2094 char (*cname)[72];
2095 double *crder;
2096 double *csyer;
2097 double *czphs;
2098 double *cperi;
2099
2100 char wcsname[72];
2101 // Time reference system and measurement.
2102 char timesys[72], trefpos[72], trefdir[72], plephem[72];
2103 char timeunit[72];
2104 char dateref[72];
2105 double mjdref[2];
2106 double timeoffs;
2107 // Data timestamps and durations.
2108 char dateobs[72], datebeg[72], dateavg[72], dateend[72];
2109 double mjdobs, mjdbeg, mjdavg, mjdend;
2110 double jepoch, bepoch;
2111 double tstart, tstop;
2112 double xposure, telapse;
2113 // Timing accuracy.
2114 double timsyer, timrder;
2115 double timedel, timepixr;
2116 // Spatial & celestial reference frame.
2117 double obsgeo[6];
2118 char obsorbit[72];
2119 char radesys[72];
2120 double equinox;
2121 char specsys[72];
2122 char ssysobs[72];
2123 double velosys;
2124 double zsource;
2125 char ssyssrc[72];
2126 double velangl;
2127
2128 // Additional auxiliary coordinate system information of a specialist
2129 // nature. Not used by WCSLIB. Refer to the prologue comments above.
2130 struct auxprm *aux;
2131
2132 // Coordinate lookup tables (see the prologue above).
2133 //--------------------------------------------------------------------------
2134 int ntab; // Number of separate tables.
2135 int nwtb; // Number of wtbarr structs.
2136 struct tabprm *tab; // Tabular transformation parameters.
2137 struct wtbarr *wtb; // Array of wtbarr structs.
2138
2139 //--------------------------------------------------------------------------
2140 // Information derived from the FITS header keyvalues by wcsset().
2141 //--------------------------------------------------------------------------
2142 char lngtyp[8], lattyp[8]; // Celestial axis types, e.g. RA, DEC.
2143 int lng, lat, spec; // Longitude, latitude and spectral axis
2144 // indices (0-relative).
2145 int cubeface; // True if there is a CUBEFACE axis.
2146 int *types; // Coordinate type codes for each axis.
2147
2148 struct linprm lin; // Linear transformation parameters.
2149 struct celprm cel; // Celestial transformation parameters.
2150 struct spcprm spc; // Spectral transformation parameters.
2151
2152 //--------------------------------------------------------------------------
2153 // THE REMAINDER OF THE WCSPRM STRUCT IS PRIVATE.
2154 //--------------------------------------------------------------------------
2155
2156 // Error handling, if enabled.
2157 //--------------------------------------------------------------------------
2158 struct wcserr *err;
2159
2160 // Memory management.
2161 //--------------------------------------------------------------------------
2162 int m_flag, m_naxis;
2163 double *m_crpix, *m_pc, *m_cdelt, *m_crval;
2164 char (*m_cunit)[72], (*m_ctype)[72];
2165 struct pvcard *m_pv;
2166 struct pscard *m_ps;
2167 double *m_cd, *m_crota;
2168 int *m_colax;
2169 char (*m_cname)[72];
2170 double *m_crder, *m_csyer, *m_czphs, *m_cperi;
2171 struct auxprm *m_aux;
2172 struct tabprm *m_tab;
2173 struct wtbarr *m_wtb;
2174};
2175
2176// Size of the wcsprm struct in int units, used by the Fortran wrappers.
2177#define WCSLEN (sizeof(struct wcsprm)/sizeof(int))
2178
2179
2180 int wcsnpv(int n);
2181
2182 int wcsnps(int n);
2183
2184 int wcsini(int alloc, int naxis, struct wcsprm *wcs);
2185
2186 int wcsinit(int alloc, int naxis, struct wcsprm *wcs, int npvmax, int npsmax,
2187 int ndpmax);
2188
2189 int wcsauxi(int alloc, struct wcsprm *wcs);
2190
2191 int wcssub(int alloc, const struct wcsprm *wcssrc, int *nsub, int axes[],
2192 struct wcsprm *wcsdst);
2193
2194 int wcscompare(int cmp, double tol, const struct wcsprm *wcs1,
2195 const struct wcsprm *wcs2, int *equal);
2196
2197 int wcsfree(struct wcsprm *wcs);
2198
2199 int wcstrim(struct wcsprm *wcs);
2200
2201 int wcssize(const struct wcsprm *wcs, int sizes[2]);
2202
2203 int auxsize(const struct auxprm *aux, int sizes[2]);
2204
2205 int wcsprt(const struct wcsprm *wcs);
2206
2207 int wcsperr(const struct wcsprm *wcs, const char *prefix);
2208
2209 int wcsbchk(struct wcsprm *wcs, int bounds);
2210
2211 int wcsset(struct wcsprm *wcs);
2212
2213 int wcsp2s(struct wcsprm *wcs, int ncoord, int nelem, const double pixcrd[],
2214 double imgcrd[], double phi[], double theta[], double world[],
2215 int stat[]);
2216
2217 int wcss2p(struct wcsprm *wcs, int ncoord, int nelem, const double world[],
2218 double phi[], double theta[], double imgcrd[], double pixcrd[],
2219 int stat[]);
2220
2221 int wcsmix(struct wcsprm *wcs, int mixpix, int mixcel, const double vspan[2],
2222 double vstep, int viter, double world[], double phi[],
2223 double theta[], double imgcrd[], double pixcrd[]);
2224
2225 int wcsccs(struct wcsprm *wcs, double lng2p1, double lat2p1, double lng1p2,
2226 const char *clng, const char *clat, const char *radesys,
2227 double equinox, const char *alt);
2228
2229 int wcssptr(struct wcsprm *wcs, int *i, char ctype[9]);
2230
2231 const char* wcslib_version(int vers[3]);
2232
2233// Defined mainly for backwards compatibility, use wcssub() instead.
2234#define wcscopy(alloc, wcssrc, wcsdst) wcssub(alloc, wcssrc, 0x0, 0x0, wcsdst)
2235
2236
2237// Deprecated.
2238#define wcsini_errmsg wcs_errmsg
2239#define wcssub_errmsg wcs_errmsg
2240#define wcscopy_errmsg wcs_errmsg
2241#define wcsfree_errmsg wcs_errmsg
2242#define wcsprt_errmsg wcs_errmsg
2243#define wcsset_errmsg wcs_errmsg
2244#define wcsp2s_errmsg wcs_errmsg
2245#define wcss2p_errmsg wcs_errmsg
2246#define wcsmix_errmsg wcs_errmsg
2247
2248#ifdef __cplusplus
2249#undef wtbarr
2250}
2251#endif
2252
2253#endif // WCSLIB_WCS
cel.h
lin.h
spc.h
auxprm
Additional auxiliary parameters.
Definition: wcs.h:2035
auxprm::dsun_obs
double dsun_obs
Definition: wcs.h:2037
auxprm::hglt_obs
double hglt_obs
Definition: wcs.h:2040
auxprm::hgln_obs
double hgln_obs
Definition: wcs.h:2039
auxprm::crln_obs
double crln_obs
Definition: wcs.h:2038
auxprm::rsun_ref
double rsun_ref
Definition: wcs.h:2036
celprm
Celestial transformation parameters.
Definition: cel.h:423
linprm
Linear transformation parameters.
Definition: lin.h:680
pscard
Store for PSi_ma keyrecords.
Definition: wcs.h:2025
pscard::i
int i
Definition: wcs.h:2026
pscard::m
int m
Definition: wcs.h:2027
pscard::value
char value[72]
Definition: wcs.h:2028
pvcard
Store for PVi_ma keyrecords.
Definition: wcs.h:2015
pvcard::value
double value
Definition: wcs.h:2018
pvcard::i
int i
Definition: wcs.h:2016
pvcard::m
int m
Definition: wcs.h:2017
spcprm
Spectral transformation parameters.
Definition: spc.h:832
tabprm
Tabular transformation parameters.
Definition: tab.h:573
wcserr
Error message handling.
Definition: wcserr.h:243
wcsprm
Coordinate transformation parameters.
Definition: wcs.h:2047
wcsprm::timeunit
char timeunit[72]
Definition: wcs.h:2103
wcsprm::m_ps
struct pscard * m_ps
Definition: wcs.h:2166
wcsprm::timesys
char timesys[72]
Definition: wcs.h:2102
wcsprm::pv
struct pvcard * pv
Definition: wcs.h:2071
wcsprm::dateref
char dateref[72]
Definition: wcs.h:2104
wcsprm::mjdavg
double mjdavg
Definition: wcs.h:2109
wcsprm::lng
int lng
Definition: wcs.h:2143
wcsprm::czphs
double * czphs
Definition: wcs.h:2097
wcsprm::m_cname
char(* m_cname)[72]
Definition: wcs.h:2169
wcsprm::zsource
double zsource
Definition: wcs.h:2124
wcsprm::m_crder
double * m_crder
Definition: wcs.h:2170
wcsprm::npv
int npv
Definition: wcs.h:2069
wcsprm::timrder
double timrder
Definition: wcs.h:2114
wcsprm::trefpos
char trefpos[72]
Definition: wcs.h:2102
wcsprm::telapse
double telapse
Definition: wcs.h:2112
wcsprm::m_csyer
double * m_csyer
Definition: wcs.h:2170
wcsprm::tstart
double tstart
Definition: wcs.h:2111
wcsprm::csyer
double * csyer
Definition: wcs.h:2096
wcsprm::m_crpix
double * m_crpix
Definition: wcs.h:2163
wcsprm::cperi
double * cperi
Definition: wcs.h:2098
wcsprm::mjdend
double mjdend
Definition: wcs.h:2109
wcsprm::wcsname
char wcsname[72]
Definition: wcs.h:2100
wcsprm::tab
struct tabprm * tab
Definition: wcs.h:2136
wcsprm::lin
struct linprm lin
Definition: wcs.h:2148
wcsprm::pc
double * pc
Definition: wcs.h:2056
wcsprm::flag
int flag
Definition: wcs.h:2050
wcsprm::aux
struct auxprm * aux
Definition: wcs.h:2130
wcsprm::npsmax
int npsmax
Definition: wcs.h:2074
wcsprm::m_cdelt
double * m_cdelt
Definition: wcs.h:2163
wcsprm::timeoffs
double timeoffs
Definition: wcs.h:2106
wcsprm::crder
double * crder
Definition: wcs.h:2095
wcsprm::nps
int nps
Definition: wcs.h:2073
wcsprm::m_colax
int * m_colax
Definition: wcs.h:2168
wcsprm::m_crval
double * m_crval
Definition: wcs.h:2163
wcsprm::timepixr
double timepixr
Definition: wcs.h:2115
wcsprm::m_crota
double * m_crota
Definition: wcs.h:2167
wcsprm::m_cperi
double * m_cperi
Definition: wcs.h:2170
wcsprm::m_flag
int m_flag
Definition: wcs.h:2162
wcsprm::lngtyp
char lngtyp[8]
Definition: wcs.h:2142
wcsprm::restwav
double restwav
Definition: wcs.h:2067
wcsprm::latpole
double latpole
Definition: wcs.h:2064
wcsprm::m_naxis
int m_naxis
Definition: wcs.h:2162
wcsprm::radesys
char radesys[72]
Definition: wcs.h:2119
wcsprm::m_pc
double * m_pc
Definition: wcs.h:2163
wcsprm::m_pv
struct pvcard * m_pv
Definition: wcs.h:2165
wcsprm::naxis
int naxis
Definition: wcs.h:2054
wcsprm::m_czphs
double * m_czphs
Definition: wcs.h:2170
wcsprm::colax
int * colax
Definition: wcs.h:2092
wcsprm::crval
double * crval
Definition: wcs.h:2058
wcsprm::m_cd
double * m_cd
Definition: wcs.h:2167
wcsprm::tstop
double tstop
Definition: wcs.h:2111
wcsprm::obsgeo
double obsgeo[6]
Definition: wcs.h:2117
wcsprm::timsyer
double timsyer
Definition: wcs.h:2114
wcsprm::nwtb
int nwtb
Definition: wcs.h:2135
wcsprm::ssyssrc
char ssyssrc[72]
Definition: wcs.h:2125
wcsprm::equinox
double equinox
Definition: wcs.h:2120
wcsprm::altlin
int altlin
Definition: wcs.h:2081
wcsprm::wtb
struct wtbarr * wtb
Definition: wcs.h:2137
wcsprm::npvmax
int npvmax
Definition: wcs.h:2070
wcsprm::cname
char(* cname)[72]
Definition: wcs.h:2094
wcsprm::jepoch
double jepoch
Definition: wcs.h:2110
wcsprm::ntab
int ntab
Definition: wcs.h:2134
wcsprm::ssysobs
char ssysobs[72]
Definition: wcs.h:2122
wcsprm::ps
struct pscard * ps
Definition: wcs.h:2075
wcsprm::colnum
int colnum
Definition: wcs.h:2091
wcsprm::datebeg
char datebeg[72]
Definition: wcs.h:2108
wcsprm::velangl
double velangl
Definition: wcs.h:2126
wcsprm::mjdbeg
double mjdbeg
Definition: wcs.h:2109
wcsprm::cunit
char(* cunit)[72]
Definition: wcs.h:2060
wcsprm::bepoch
double bepoch
Definition: wcs.h:2110
wcsprm::mjdref
double mjdref[2]
Definition: wcs.h:2105
wcsprm::trefdir
char trefdir[72]
Definition: wcs.h:2102
wcsprm::plephem
char plephem[72]
Definition: wcs.h:2102
wcsprm::dateobs
char dateobs[72]
Definition: wcs.h:2108
wcsprm::crpix
double * crpix
Definition: wcs.h:2055
wcsprm::types
int * types
Definition: wcs.h:2146
wcsprm::lat
int lat
Definition: wcs.h:2143
wcsprm::spec
int spec
Definition: wcs.h:2143
wcsprm::specsys
char specsys[72]
Definition: wcs.h:2121
wcsprm::mjdobs
double mjdobs
Definition: wcs.h:2109
wcsprm::xposure
double xposure
Definition: wcs.h:2112
wcsprm::velref
int velref
Definition: wcs.h:2085
wcsprm::cel
struct celprm cel
Definition: wcs.h:2149
wcsprm::m_wtb
struct wtbarr * m_wtb
Definition: wcs.h:2173
wcsprm::dateend
char dateend[72]
Definition: wcs.h:2108
wcsprm::m_aux
struct auxprm * m_aux
Definition: wcs.h:2171
wcsprm::restfrq
double restfrq
Definition: wcs.h:2066
wcsprm::cdelt
double * cdelt
Definition: wcs.h:2057
wcsprm::cubeface
int cubeface
Definition: wcs.h:2145
wcsprm::m_tab
struct tabprm * m_tab
Definition: wcs.h:2172
wcsprm::obsorbit
char obsorbit[72]
Definition: wcs.h:2118
wcsprm::ctype
char(* ctype)[72]
Definition: wcs.h:2061
wcsprm::lattyp
char lattyp[8]
Definition: wcs.h:2142
wcsprm::dateavg
char dateavg[72]
Definition: wcs.h:2108
wcsprm::alt
char alt[4]
Definition: wcs.h:2090
wcsprm::spc
struct spcprm spc
Definition: wcs.h:2150
wcsprm::timedel
double timedel
Definition: wcs.h:2115
wcsprm::crota
double * crota
Definition: wcs.h:2080
wcsprm::m_cunit
char(* m_cunit)[72]
Definition: wcs.h:2164
wcsprm::velosys
double velosys
Definition: wcs.h:2123
wcsprm::err
struct wcserr * err
Definition: wcs.h:2158
wcsprm::lonpole
double lonpole
Definition: wcs.h:2063
wcsprm::cd
double * cd
Definition: wcs.h:2079
wtbarr
Extraction of coordinate lookup tables from BINTABLE.
Definition: getwcstab.h:167
wtbarr::i
int i
Definition: getwcstab.h:168
wcs_errmsg_enum
wcs_errmsg_enum
Definition: wcs.h:1989
WCSERR_BAD_WORLD
@ WCSERR_BAD_WORLD
Definition: wcs.h:2003
WCSERR_BAD_PIX
@ WCSERR_BAD_PIX
Definition: wcs.h:2001
WCSERR_SINGULAR_MTX
@ WCSERR_SINGULAR_MTX
Definition: wcs.h:1993
WCSERR_NON_SEPARABLE
@ WCSERR_NON_SEPARABLE
Definition: wcs.h:2009
WCSERR_BAD_CTYPE
@ WCSERR_BAD_CTYPE
Definition: wcs.h:1994
WCSERR_MEMORY
@ WCSERR_MEMORY
Definition: wcs.h:1992
WCSERR_BAD_WORLD_COORD
@ WCSERR_BAD_WORLD_COORD
Definition: wcs.h:2005
WCSERR_BAD_COORD_TRANS
@ WCSERR_BAD_COORD_TRANS
Definition: wcs.h:1997
WCSERR_NO_SOLUTION
@ WCSERR_NO_SOLUTION
Definition: wcs.h:2006
WCSERR_BAD_SUBIMAGE
@ WCSERR_BAD_SUBIMAGE
Definition: wcs.h:2008
WCSERR_SUCCESS
@ WCSERR_SUCCESS
Definition: wcs.h:1990
WCSERR_UNSET
@ WCSERR_UNSET
Definition: wcs.h:2010
WCSERR_NULL_POINTER
@ WCSERR_NULL_POINTER
Definition: wcs.h:1991
WCSERR_ILL_COORD_TRANS
@ WCSERR_ILL_COORD_TRANS
Definition: wcs.h:1999
WCSERR_BAD_PARAM
@ WCSERR_BAD_PARAM
Definition: wcs.h:1996
wcsmix
int wcsmix(struct wcsprm *wcs, int mixpix, int mixcel, const double vspan[2], double vstep, int viter, double world[], double phi[], double theta[], double imgcrd[], double pixcrd[])
Hybrid coordinate transformation.
wcsp2s
int wcsp2s(struct wcsprm *wcs, int ncoord, int nelem, const double pixcrd[], double imgcrd[], double phi[], double theta[], double world[], int stat[])
Pixel-to-world transformation.
wcsini
int wcsini(int alloc, int naxis, struct wcsprm *wcs)
Default constructor for the wcsprm struct.
wcssize
int wcssize(const struct wcsprm *wcs, int sizes[2])
Compute the size of a wcsprm struct.
wcsnpv
int wcsnpv(int n)
Memory allocation for PVi_ma.
wcsfree
int wcsfree(struct wcsprm *wcs)
Destructor for the wcsprm struct.
auxsize
int auxsize(const struct auxprm *aux, int sizes[2])
Compute the size of a auxprm struct.
wcssptr
int wcssptr(struct wcsprm *wcs, int *i, char ctype[9])
Spectral axis translation.
wcss2p
int wcss2p(struct wcsprm *wcs, int ncoord, int nelem, const double world[], double phi[], double theta[], double imgcrd[], double pixcrd[], int stat[])
World-to-pixel transformation.
wcscompare
int wcscompare(int cmp, double tol, const struct wcsprm *wcs1, const struct wcsprm *wcs2, int *equal)
Compare two wcsprm structs for equality.
wcsccs
int wcsccs(struct wcsprm *wcs, double lng2p1, double lat2p1, double lng1p2, const char *clng, const char *clat, const char *radesys, double equinox, const char *alt)
Change celestial coordinate system.
wcssub
int wcssub(int alloc, const struct wcsprm *wcssrc, int *nsub, int axes[], struct wcsprm *wcsdst)
Subimage extraction routine for the wcsprm struct.
wcsperr
int wcsperr(const struct wcsprm *wcs, const char *prefix)
Print error messages from a wcsprm struct.
wcsauxi
int wcsauxi(int alloc, struct wcsprm *wcs)
Default constructor for the auxprm struct.
wcsinit
int wcsinit(int alloc, int naxis, struct wcsprm *wcs, int npvmax, int npsmax, int ndpmax)
Default constructor for the wcsprm struct.
wcstrim
int wcstrim(struct wcsprm *wcs)
Free unused arrays in the wcsprm struct.
wcsprt
int wcsprt(const struct wcsprm *wcs)
Print routine for the wcsprm struct.
wcs_errmsg
const char * wcs_errmsg[]
Status return messages.
wcslib_version
const char * wcslib_version(int vers[3])
wcsset
int wcsset(struct wcsprm *wcs)
Setup routine for the wcsprm struct.
wcsnps
int wcsnps(int n)
Memory allocation for PSi_ma.
wcsbchk
int wcsbchk(struct wcsprm *wcs, int bounds)
Enable/disable bounds checking.