# dsptrs.f man page

dsptrs.f

## Synopsis

### Functions/Subroutines

subroutine **dsptrs** (UPLO, **N**, **NRHS**, AP, IPIV, B, **LDB**, INFO)**DSPTRS**

## Function/Subroutine Documentation

### subroutine dsptrs (character UPLO, integer N, integer NRHS, double precision, dimension( * ) AP, integer, dimension( * ) IPIV, double precision, dimension( ldb, * ) B, integer LDB, integer INFO)

**DSPTRS**

**Purpose:**

DSPTRS solves a system of linear equations A*X = B with a real symmetric matrix A stored in packed format using the factorization A = U*D*U**T or A = L*D*L**T computed by DSPTRF.

**Parameters:***UPLO*UPLO is CHARACTER*1 Specifies whether the details of the factorization are stored as an upper or lower triangular matrix. = 'U': Upper triangular, form is A = U*D*U**T; = 'L': Lower triangular, form is A = L*D*L**T.

*N*N is INTEGER The order of the matrix A. N >= 0.

*NRHS*NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.

*AP*AP is DOUBLE PRECISION array, dimension (N*(N+1)/2) The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSPTRF, stored as a packed triangular matrix.

*IPIV*IPIV is INTEGER array, dimension (N) Details of the interchanges and the block structure of D as determined by DSPTRF.

*B*B is DOUBLE PRECISION array, dimension (LDB,NRHS) On entry, the right hand side matrix B. On exit, the solution matrix X.

*LDB*LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N).

*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:**December 2016

Definition at line 117 of file dsptrs.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dsptrs(3) is an alias of dsptrs.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK