TESTING/LIN/dpbt02.f(3) Library Functions Manual TESTING/LIN/dpbt02.f(3) NAME TESTING/LIN/dpbt02.f SYNOPSIS Functions/Subroutines subroutine dpbt02 (uplo, n, kd, nrhs, a, lda, x, ldx, b, ldb, rwork, resid) DPBT02 Function/Subroutine Documentation subroutine dpbt02 (character uplo, integer n, integer kd, integer nrhs, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldx, * ) x, integer ldx, double precision, dimension( ldb, * ) b, integer ldb, double precision, dimension( * ) rwork, double precision resid) DPBT02 Purpose: DPBT02 computes the residual for a solution of a symmetric 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 symmetric 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 DOUBLE PRECISION array, dimension (LDA,N) The original symmetric 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 DPBTRF for further details. LDA LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,KD+1). X X is DOUBLE PRECISION 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 DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (N) RESID RESID is DOUBLE PRECISION 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 dpbt02.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/LIN/dpbt02.f(3)