sget39.f - Man Page
TESTING/EIG/sget39.f
Synopsis
Functions/Subroutines
subroutine sget39 (rmax, lmax, ninfo, knt)
SGET39
Function/Subroutine Documentation
subroutine sget39 (real rmax, integer lmax, integer ninfo, integer knt)
SGET39
Purpose:
SGET39 tests SLAQTR, a routine for solving the real or special complex quasi upper triangular system op(T)*p = scale*c, or op(T + iB)*(p+iq) = scale*(c+id), in real arithmetic. T is upper quasi-triangular. If it is complex, then the first diagonal block of T must be 1 by 1, B has the special structure B = [ b(1) b(2) ... b(n) ] [ w ] [ w ] [ . ] [ w ] op(A) = A or A', where A' denotes the conjugate transpose of the matrix A. On input, X = [ c ]. On output, X = [ p ]. [ d ] [ q ] Scale is an output less than or equal to 1, chosen to avoid overflow in X. This subroutine is specially designed for the condition number estimation in the eigenproblem routine STRSNA. The test code verifies that the following residual is order 1: ||(T+i*B)*(x1+i*x2) - scale*(d1+i*d2)|| ----------------------------------------- max(ulp*(||T||+||B||)*(||x1||+||x2||), (||T||+||B||)*smlnum/ulp, smlnum) (The (||T||+||B||)*smlnum/ulp term accounts for possible (gradual or nongradual) underflow in x1 and x2.)
- Parameters
RMAX
RMAX is REAL Value of the largest test ratio.
LMAX
LMAX is INTEGER Example number where largest test ratio achieved.
NINFO
NINFO is INTEGER Number of examples where INFO is nonzero.
KNT
KNT is INTEGER Total number of examples tested.
- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 102 of file sget39.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Referenced By
The man page sget39(3) is an alias of sget39.f(3).
Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK