TESTING/LIN/cpbt02.f(3) Library Functions Manual TESTING/LIN/cpbt02.f(3) NAME TESTING/LIN/cpbt02.f SYNOPSIS Functions/Subroutines subroutine cpbt02 (uplo, n, kd, nrhs, a, lda, x, ldx, b, ldb, rwork, resid) CPBT02 Function/Subroutine Documentation subroutine cpbt02 (character uplo, integer n, integer kd, 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) CPBT02 Purpose: CPBT02 computes the residual for a solution of a Hermitian banded system of equations A*x = b: RESID = norm( B - A*X ) / ( norm(A) * norm(X) * EPS) where EPS is the machine precision. Parameters UPLO UPLO is CHARACTER*1 Specifies whether the upper or lower triangular part of the Hermitian matrix A is stored: = 'U': Upper triangular = 'L': Lower triangular N N is INTEGER The number of rows and columns of the matrix A. N >= 0. KD KD is INTEGER The number of super-diagonals of the matrix A if UPLO = 'U', or the number of sub-diagonals if UPLO = 'L'. KD >= 0. NRHS NRHS is INTEGER The number of right hand sides. NRHS >= 0. A A is COMPLEX array, dimension (LDA,N) The original Hermitian band matrix A. If UPLO = 'U', the upper triangular part of A is stored as a band matrix; if UPLO = 'L', the lower triangular part of A is stored. The columns of the appropriate triangle are stored in the columns of A and the diagonals of the triangle are stored in the rows of A. See CPBTRF for further details. LDA LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,KD+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. LDX >= max(1,N). 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. LDB >= max(1,N). RWORK RWORK is REAL array, dimension (N) RESID RESID is REAL The maximum over the number of right hand sides of norm(B - A*X) / ( norm(A) * norm(X) * EPS ). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line 134 of file cpbt02.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/LIN/cpbt02.f(3)