# dsytrs_aa_2stage.f - Man Page

## Synopsis

### Functions/Subroutines

subroutine **dsytrs_aa_2stage** (UPLO, **N**, **NRHS**, A, **LDA**, TB, LTB, IPIV, IPIV2, B, **LDB**, INFO)**DSYTRS_AA_2STAGE**

## Function/Subroutine Documentation

### subroutine dsytrs_aa_2stage (character UPLO, integer N, integer NRHS, double precision, dimension( lda, * ) A, integer LDA, double precision, dimension( * ) TB, integer LTB, integer, dimension( * ) IPIV, integer, dimension( * ) IPIV2, double precision, dimension( ldb, * ) B, integer LDB, integer INFO)

**DSYTRS_AA_2STAGE**

**Purpose:**

DSYTRS_AA_2STAGE solves a system of linear equations A*X = B with a real symmetric matrix A using the factorization A = U*T*U**T or A = L*T*L**T computed by DSYTRF_AA_2STAGE.

**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*T*U**T; = 'L': Lower triangular, form is A = L*T*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.

*A*A is DOUBLE PRECISION array, dimension (LDA,N) Details of factors computed by DSYTRF_AA_2STAGE.

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

*TB*TB is DOUBLE PRECISION array, dimension (LTB) Details of factors computed by DSYTRF_AA_2STAGE.

*LTB*The size of the array TB. LTB >= 4*N.

*IPIV*IPIV is INTEGER array, dimension (N) Details of the interchanges as computed by DSYTRF_AA_2STAGE.

*IPIV2*IPIV2 is INTEGER array, dimension (N) Details of the interchanges as computed by DSYTRF_AA_2STAGE.

*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:**November 2017

Definition at line 140 of file dsytrs_aa_2stage.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page dsytrs_aa_2stage(3) is an alias of dsytrs_aa_2stage.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK