#include "blaswrap.h" /* ztrt01.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 integer c__1 = 1; /* Subroutine */ int ztrt01_(char *uplo, char *diag, integer *n, doublecomplex *a, integer *lda, doublecomplex *ainv, integer *ldainv, doublereal *rcond, doublereal *rwork, doublereal *resid ) { /* System generated locals */ integer a_dim1, a_offset, ainv_dim1, ainv_offset, i__1, i__2, i__3; doublecomplex z__1; /* Local variables */ static integer j; static doublereal eps; extern logical lsame_(char *, char *); static doublereal anorm; extern /* Subroutine */ int ztrmv_(char *, char *, char *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); extern doublereal dlamch_(char *); static doublereal ainvnm; extern doublereal zlantr_(char *, char *, char *, integer *, integer *, doublecomplex *, integer *, doublereal *); /* -- LAPACK test routine (version 3.1) -- Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. November 2006 Purpose ======= ZTRT01 computes the residual for a triangular matrix A times its inverse: RESID = norm( A*AINV - I ) / ( N * norm(A) * norm(AINV) * EPS ), where EPS is the machine epsilon. Arguments ========== UPLO (input) CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular DIAG (input) CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular N (input) INTEGER The order of the matrix A. N >= 0. A (input) COMPLEX*16 array, dimension (LDA,N) The triangular matrix A. If UPLO = 'U', the leading n by n upper triangular part of the array A contains the upper triangular matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n by n lower triangular part of the array A contains the lower triangular matrix, and the strictly upper triangular part of A is not referenced. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). AINV (input) COMPLEX*16 array, dimension (LDAINV,N) On entry, the (triangular) inverse of the matrix A, in the same storage format as A. On exit, the contents of AINV are destroyed. LDAINV (input) INTEGER The leading dimension of the array AINV. LDAINV >= max(1,N). RCOND (output) DOUBLE PRECISION The reciprocal condition number of A, computed as 1/(norm(A) * norm(AINV)). RWORK (workspace) DOUBLE PRECISION array, dimension (N) RESID (output) DOUBLE PRECISION norm(A*AINV - I) / ( 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; --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 = zlantr_("1", uplo, diag, n, n, &a[a_offset], lda, &rwork[1]); ainvnm = zlantr_("1", uplo, diag, n, n, &ainv[ainv_offset], ldainv, & rwork[1]); if (anorm <= 0. || ainvnm <= 0.) { *rcond = 0.; *resid = 1. / eps; return 0; } *rcond = 1. / anorm / ainvnm; /* Set the diagonal of AINV to 1 if AINV has unit diagonal. */ if (lsame_(diag, "U")) { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = j + j * ainv_dim1; ainv[i__2].r = 1., ainv[i__2].i = 0.; /* L10: */ } } /* Compute A * AINV, overwriting AINV. */ if (lsame_(uplo, "U")) { i__1 = *n; for (j = 1; j <= i__1; ++j) { ztrmv_("Upper", "No transpose", diag, &j, &a[a_offset], lda, & ainv[j * ainv_dim1 + 1], &c__1); /* L20: */ } } else { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *n - j + 1; ztrmv_("Lower", "No transpose", diag, &i__2, &a[j + j * a_dim1], lda, &ainv[j + j * ainv_dim1], &c__1); /* L30: */ } } /* Subtract 1 from each diagonal element to form A*AINV - I. */ i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = j + j * ainv_dim1; i__3 = j + j * ainv_dim1; z__1.r = ainv[i__3].r - 1., z__1.i = ainv[i__3].i; ainv[i__2].r = z__1.r, ainv[i__2].i = z__1.i; /* L40: */ } /* Compute norm(A*AINV - I) / (N * norm(A) * norm(AINV) * EPS) */ *resid = zlantr_("1", uplo, "Non-unit", n, n, &ainv[ainv_offset], ldainv, &rwork[1]); *resid = *resid * *rcond / (doublereal) (*n) / eps; return 0; /* End of ZTRT01 */ } /* ztrt01_ */