TESTING/LIN/sppt02.f(3) | Library Functions Manual | TESTING/LIN/sppt02.f(3) |
NAME
TESTING/LIN/sppt02.f
SYNOPSIS
Functions/Subroutines
subroutine sppt02 (uplo, n, nrhs, a, x, ldx, b, ldb, rwork,
resid)
SPPT02
Function/Subroutine Documentation
subroutine sppt02 (character uplo, integer n, integer nrhs, real, dimension( * ) a, real, dimension( ldx, * ) x, integer ldx, real, dimension( ldb, * ) b, integer ldb, real, dimension( * ) rwork, real resid)
SPPT02
Purpose:
SPPT02 computes the residual in the solution of a symmetric system of linear equations A*x = b when packed storage is used for the coefficient matrix. The ratio computed is 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.
NRHS
NRHS is INTEGER The number of columns of B, the matrix of right hand sides. NRHS >= 0.
A
A is REAL array, dimension (N*(N+1)/2) The original symmetric matrix A, stored as a packed triangular matrix.
X
X is REAL 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 REAL 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 120 of file sppt02.f.
Author
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