# dsytrs_rook.f man page

dsytrs_rook.f —

## Synopsis

### Functions/Subroutines

subroutinedsytrs_rook(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, INFO)DSYTRS_ROOK

## Function/Subroutine Documentation

### subroutine dsytrs_rook (characterUPLO, integerN, integerNRHS, double precision, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, double precision, dimension( ldb, * )B, integerLDB, integerINFO)

**DSYTRS_ROOK**

**Purpose:**

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

**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.
```

*A*

```
A is DOUBLE PRECISION array, dimension (LDA,N)
The block diagonal matrix D and the multipliers used to
obtain the factor U or L as computed by DSYTRF_ROOK.
```

*LDA*

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

*IPIV*

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

*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:**

April 2012

**Contributors:**

```
April 2012, Igor Kozachenko,
Computer Science Division,
University of California, Berkeley
September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas,
School of Mathematics,
University of Manchester
```

Definition at line 136 of file dsytrs_rook.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

dsytrs_rook(3) is an alias of dsytrs_rook.f(3).