cspt02()

subroutine cspt02	(	character	UPLO,
		integer	N,
		integer	NRHS,
		complex, dimension( * )	A,
		complex, dimension( ldx, * )	X,
		integer	LDX,
		complex, dimension( ldb, * )	B,
		integer	LDB,
		real, dimension( * )	RWORK,
		real	RESID
	)

CSPT02

Purpose:

 CSPT02 computes the residual in the solution of a complex 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

[in]	UPLO	UPLO is CHARACTER*1 Specifies whether the upper or lower triangular part of the complex symmetric matrix A is stored: = 'U': Upper triangular = 'L': Lower triangular
[in]	N	N is INTEGER The number of rows and columns of the matrix A. N >= 0.
[in]	NRHS	NRHS is INTEGER The number of columns of B, the matrix of right hand sides. NRHS >= 0.
[in]	A	A is COMPLEX array, dimension (N*(N+1)/2) The original complex symmetric matrix A, stored as a packed triangular matrix.
[in]	X	X is COMPLEX array, dimension (LDX,NRHS) The computed solution vectors for the system of linear equations.
[in]	LDX	LDX is INTEGER The leading dimension of the array X. LDX >= max(1,N).
[in,out]	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.
[in]	LDB	LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N).
[out]	RWORK	RWORK is REAL array, dimension (N)
[out]	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.