TESTING/LIN/cgbt02.f(3) Library Functions Manual TESTING/LIN/cgbt02.f(3) NAME TESTING/LIN/cgbt02.f SYNOPSIS Functions/Subroutines subroutine cgbt02 (trans, m, n, kl, ku, nrhs, a, lda, x, ldx, b, ldb, rwork, resid) CGBT02 Function/Subroutine Documentation subroutine cgbt02 (character trans, integer m, integer n, integer kl, integer ku, integer nrhs, complex, dimension( lda, * ) a, integer lda, complex, dimension( ldx, * ) x, integer ldx, complex, dimension( ldb, * ) b, integer ldb, real, dimension( * ) rwork, real resid) CGBT02 Purpose: CGBT02 computes the residual for a solution of a banded system of equations op(A)*X = B: RESID = norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ), where op(A) = A, A**T, or A**H, depending on TRANS, and EPS is the machine epsilon. Parameters TRANS TRANS is CHARACTER*1 Specifies the form of the system of equations: = 'N': A * X = B (No transpose) = 'T': A**T * X = B (Transpose) = 'C': A**H * X = B (Conjugate transpose) M M is INTEGER The number of rows of the matrix A. M >= 0. N N is INTEGER The number of columns of the matrix A. N >= 0. KL KL is INTEGER The number of subdiagonals within the band of A. KL >= 0. KU KU is INTEGER The number of superdiagonals within the band of A. KU >= 0. NRHS NRHS is INTEGER The number of columns of B. NRHS >= 0. A A is COMPLEX array, dimension (LDA,N) The original matrix A in band storage, stored in rows 1 to KL+KU+1. LDA LDA is INTEGER The leading dimension of the array A. LDA >= max(1,KL+KU+1). X X is COMPLEX 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. If TRANS = 'N', LDX >= max(1,N); if TRANS = 'T' or 'C', LDX >= max(1,M). B B is COMPLEX array, dimension (LDB,NRHS) On entry, the right hand side vectors for the system of linear equations. On exit, B is overwritten with the difference B - A*X. LDB LDB is INTEGER The leading dimension of the array B. IF TRANS = 'N', LDB >= max(1,M); if TRANS = 'T' or 'C', LDB >= max(1,N). RWORK RWORK is REAL array, dimension (MAX(1,LRWORK)), where LRWORK >= M when TRANS = 'T' or 'C'; otherwise, RWORK is not referenced. RESID RESID is REAL The maximum over the number of right hand sides of norm(B - op(A)*X) / ( norm(op(A)) * norm(X) * EPS ). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line 146 of file cgbt02.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/LIN/cgbt02.f(3)