spptrs.f File Reference

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Functions/Subroutines
subroutine	spptrs (UPLO, N, NRHS, AP, B, LDB, INFO)
	SPPTRS

---

Function/Subroutine Documentation

subroutine spptrs	(	character	UPLO,
		integer	N,
		integer	NRHS,
		real, dimension( * )	AP,
		real, dimension( ldb, * )	B,
		integer	LDB,
		integer	INFO
	)

SPPTRS

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Purpose:

 SPPTRS solves a system of linear equations A*X = B with a symmetric
 positive definite matrix A in packed storage using the Cholesky
 factorization A = U**T*U or A = L*L**T computed by SPPTRF.

Parameters:

[in]	UPLO	UPLO is CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored.
[in]	N	N is INTEGER The order of the matrix A. N >= 0.
[in]	NRHS	NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
[in]	AP	AP is REAL array, dimension (N*(N+1)/2) The triangular factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T, packed columnwise in a linear array. The j-th column of U or L is stored in the array AP as follows: if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.
[in,out]	B	B is REAL array, dimension (LDB,NRHS) On entry, the right hand side matrix B. On exit, the solution matrix X.
[in]	LDB	LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N).
[out]	INFO	INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Definition at line 109 of file spptrs.f.

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