TESTING/EIG/ssyl01.f(3)

NAME
TESTING/EIG/ssyl01.f

SYNOPSIS

  Functions/Subroutines
subroutine ssyl01 (thresh, nfail, rmax, ninfo, knt)
SSYL01

Function/Subroutine Documentation

  subroutine ssyl01 (real thresh, integer, dimension( 3 ) nfail, real, dimension( 2 ) rmax, integer, dimension( 2 ) ninfo, integer knt)

SSYL01

Purpose:

     SSYL01 tests STRSYL and STRSYL3, routines for solving the Sylvester matrix
     equation
        op(A)*X + ISGN*X*op(B) = scale*C,
     A and B are assumed to be in Schur canonical form, op() represents an
     optional transpose, and ISGN can be -1 or +1.  Scale is an output
     less than or equal to 1, chosen to avoid overflow in X.
     The test code verifies that the following residual does not exceed
     the provided threshold:
        norm(op(A)*X + ISGN*X*op(B) - scale*C) /
            (EPS*max(norm(A),norm(B))*norm(X))
     This routine complements SGET35 by testing with larger,
     random matrices, of which some require rescaling of X to avoid overflow.

Parameters
    THRESH

              THRESH is REAL
              A test will count as 'failed' if the residual, computed as
              described above, exceeds THRESH.

    NFAIL

              NFAIL is INTEGER array, dimension (3)
              NFAIL(1) = No. of times residual STRSYL exceeds threshold THRESH
              NFAIL(2) = No. of times residual STRSYL3 exceeds threshold THRESH
              NFAIL(3) = No. of times STRSYL3 and STRSYL deviate

    RMAX

              RMAX is REAL, dimension (2)
              RMAX(1) = Value of the largest test ratio of STRSYL
              RMAX(2) = Value of the largest test ratio of STRSYL3

    NINFO

              NINFO is INTEGER array, dimension (2)
              NINFO(1) = No. of times STRSYL returns an expected INFO
              NINFO(2) = No. of times STRSYL3 returns an expected INFO

    KNT

              KNT is INTEGER
              Total number of examples tested.

Definition at line 88 of file ssyl01.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.