#include "blaswrap.h" /* zget03.f -- translated by f2c (version 20061008). You must link the resulting object file with libf2c: on Microsoft Windows system, link with libf2c.lib; on Linux or Unix systems, link with .../path/to/libf2c.a -lm or, if you install libf2c.a in a standard place, with -lf2c -lm -- in that order, at the end of the command line, as in cc *.o -lf2c -lm Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., http://www.netlib.org/f2c/libf2c.zip */ #include "f2c.h" /* Table of constant values */ static doublecomplex c_b1 = {0.,0.}; /* Subroutine */ int zget03_(integer *n, doublecomplex *a, integer *lda, doublecomplex *ainv, integer *ldainv, doublecomplex *work, integer * ldwork, doublereal *rwork, doublereal *rcond, doublereal *resid) { /* System generated locals */ integer a_dim1, a_offset, ainv_dim1, ainv_offset, work_dim1, work_offset, i__1, i__2, i__3; doublecomplex z__1; /* Local variables */ static integer i__; static doublereal eps, anorm; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); extern doublereal dlamch_(char *), zlange_(char *, integer *, integer *, doublecomplex *, integer *, doublereal *); static doublereal ainvnm; /* -- LAPACK test routine (version 3.1) -- Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. November 2006 Purpose ======= ZGET03 computes the residual for a general matrix times its inverse: norm( I - AINV*A ) / ( N * norm(A) * norm(AINV) * EPS ), where EPS is the machine epsilon. Arguments ========== N (input) INTEGER The number of rows and columns of the matrix A. N >= 0. A (input) COMPLEX*16 array, dimension (LDA,N) The original N x N matrix A. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). AINV (input) COMPLEX*16 array, dimension (LDAINV,N) The inverse of the matrix A. LDAINV (input) INTEGER The leading dimension of the array AINV. LDAINV >= max(1,N). WORK (workspace) COMPLEX*16 array, dimension (LDWORK,N) LDWORK (input) INTEGER The leading dimension of the array WORK. LDWORK >= max(1,N). RWORK (workspace) DOUBLE PRECISION array, dimension (N) RCOND (output) DOUBLE PRECISION The reciprocal of the condition number of A, computed as ( 1/norm(A) ) / norm(AINV). RESID (output) DOUBLE PRECISION norm(I - AINV*A) / ( N * norm(A) * norm(AINV) * EPS ) ===================================================================== Quick exit if N = 0. Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; ainv_dim1 = *ldainv; ainv_offset = 1 + ainv_dim1; ainv -= ainv_offset; work_dim1 = *ldwork; work_offset = 1 + work_dim1; work -= work_offset; --rwork; /* Function Body */ if (*n <= 0) { *rcond = 1.; *resid = 0.; return 0; } /* Exit with RESID = 1/EPS if ANORM = 0 or AINVNM = 0. */ eps = dlamch_("Epsilon"); anorm = zlange_("1", n, n, &a[a_offset], lda, &rwork[1]); ainvnm = zlange_("1", n, n, &ainv[ainv_offset], ldainv, &rwork[1]); if (anorm <= 0. || ainvnm <= 0.) { *rcond = 0.; *resid = 1. / eps; return 0; } *rcond = 1. / anorm / ainvnm; /* Compute I - A * AINV */ z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "No transpose", n, n, n, &z__1, &ainv[ainv_offset], ldainv, &a[a_offset], lda, &c_b1, &work[work_offset], ldwork); i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + i__ * work_dim1; i__3 = i__ + i__ * work_dim1; z__1.r = work[i__3].r + 1., z__1.i = work[i__3].i + 0.; work[i__2].r = z__1.r, work[i__2].i = z__1.i; /* L10: */ } /* Compute norm(I - AINV*A) / (N * norm(A) * norm(AINV) * EPS) */ *resid = zlange_("1", n, n, &work[work_offset], ldwork, &rwork[1]); *resid = *resid * *rcond / eps / (doublereal) (*n); return 0; /* End of ZGET03 */ } /* zget03_ */