|
Qwt User's Guide
6.1.4
|
A class for spline interpolation. More...
#include <qwt_spline.h>
Public Types | |
| enum | SplineType { Natural, Periodic } |
| Spline type. More... | |
Public Member Functions | |
| QwtSpline () | |
| Constructor. | |
| QwtSpline (const QwtSpline &) | |
| ~QwtSpline () | |
| Destructor. | |
| QwtSpline & | operator= (const QwtSpline &) |
| void | setSplineType (SplineType) |
| SplineType | splineType () const |
| bool | setPoints (const QPolygonF &points) |
| Calculate the spline coefficients. More... | |
| QPolygonF | points () const |
| void | reset () |
| Free allocated memory and set size to 0. | |
| bool | isValid () const |
| True if valid. | |
| double | value (double x) const |
| const QVector< double > & | coefficientsA () const |
| const QVector< double > & | coefficientsB () const |
| const QVector< double > & | coefficientsC () const |
Protected Member Functions | |
| bool | buildNaturalSpline (const QPolygonF &) |
| Determines the coefficients for a natural spline. More... | |
| bool | buildPeriodicSpline (const QPolygonF &) |
| Determines the coefficients for a periodic spline. More... | |
A class for spline interpolation.
The QwtSpline class is used for cubical spline interpolation. Two types of splines, natural and periodic, are supported.
| QwtSpline::QwtSpline | ( | const QwtSpline & | other | ) |
Copy constructor
| other | Spline used for initialization |
|
protected |
Determines the coefficients for a natural spline.
|
protected |
Determines the coefficients for a periodic spline.
| const QVector< double > & QwtSpline::coefficientsA | ( | ) | const |
| const QVector< double > & QwtSpline::coefficientsB | ( | ) | const |
| const QVector< double > & QwtSpline::coefficientsC | ( | ) | const |
Assignment operator
| other | Spline used for initialization |
| QPolygonF QwtSpline::points | ( | ) | const |
| bool QwtSpline::setPoints | ( | const QPolygonF & | points | ) |
Calculate the spline coefficients.
Depending on the value of periodic, this function will determine the coefficients for a natural or a periodic spline and store them internally.
| points | Points |
points[i].x() < points[i+1].x(). If this is not the case, the function will return false | void QwtSpline::setSplineType | ( | SplineType | splineType | ) |
Select the algorithm used for calculating the spline
| splineType | Spline type |
| QwtSpline::SplineType QwtSpline::splineType | ( | ) | const |
| double QwtSpline::value | ( | double | x | ) | const |
Calculate the interpolated function value corresponding to a given argument x.
| x | Coordinate |