dpbt02.f - Man Page
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.
Referenced By
The man page dpbt02(3) is an alias of dpbt02.f(3).
Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK