TESTING/LIN/ztrt02.f(3) Library Functions Manual TESTING/LIN/ztrt02.f(3) NAME TESTING/LIN/ztrt02.f SYNOPSIS Functions/Subroutines subroutine ztrt02 (uplo, trans, diag, n, nrhs, a, lda, x, ldx, b, ldb, work, rwork, resid) ZTRT02 Function/Subroutine Documentation subroutine ztrt02 (character uplo, character trans, character diag, integer n, integer nrhs, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( ldx, * ) x, integer ldx, complex*16, dimension( ldb, * ) b, integer ldb, complex*16, dimension( * ) work, double precision, dimension( * ) rwork, double precision resid) ZTRT02 Purpose: ZTRT02 computes the residual for the computed solution to a triangular system of linear equations op(A)*X = B, where A is a triangular matrix. The test ratio is the maximum over norm(b - op(A)*x) / ( ||op(A)||_1 * norm(x) * EPS ), where op(A) = A, A**T, or A**H, b is the column of B, x is the solution vector, and EPS is the machine epsilon. Parameters UPLO UPLO is CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular TRANS TRANS is CHARACTER*1 Specifies the operation applied to A. = 'N': A * X = B (No transpose) = 'T': A**T * X = B (Transpose) = 'C': A**H * X = B (Conjugate transpose) DIAG DIAG is CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular N N is INTEGER The order of the matrix A. N >= 0. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrices X and B. NRHS >= 0. A A is 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 LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). X X is COMPLEX*16 array, dimension (LDX,NRHS) The computed solution vectors for the system of linear equations. LDX LDX is INTEGER The leading dimension of the array X. LDX >= max(1,N). B B is COMPLEX*16 array, dimension (LDB,NRHS) The right hand side vectors for the system of linear equations. LDB LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). WORK WORK is COMPLEX*16 array, dimension (N) RWORK RWORK is DOUBLE PRECISION array, dimension (N) RESID RESID is DOUBLE PRECISION The maximum over the number of right hand sides of norm(op(A)*X - B) / ( norm(op(A)) * norm(X) * EPS ). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line 153 of file ztrt02.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/LIN/ztrt02.f(3)