# cheswapr.f

Section: LAPACK (3)
Updated: Tue Nov 14 2017
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cheswapr.f

## SYNOPSIS

### Functions/Subroutines

subroutine cheswapr (UPLO, N, A, LDA, I1, I2)
CHESWAPR applies an elementary permutation on the rows and columns of a Hermitian matrix.

## Function/Subroutine Documentation

### subroutine cheswapr (character UPLO, integer N, complex, dimension( lda, n ) A, integer LDA, integer I1, integer I2)

CHESWAPR applies an elementary permutation on the rows and columns of a Hermitian matrix.

Purpose:

``` CHESWAPR applies an elementary permutation on the rows and the columns of
a hermitian matrix.
```

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.
```

A

```          A is COMPLEX array, dimension (LDA,N)
On entry, the NB diagonal matrix D and the multipliers
used to obtain the factor U or L as computed by CSYTRF.

On exit, if INFO = 0, the (symmetric) inverse of the original
matrix.  If UPLO = 'U', the upper triangular part of the
inverse is formed and the part of A below the diagonal is not
referenced; if UPLO = 'L' the lower triangular part of the
inverse is formed and the part of A above the diagonal is
not referenced.
```

LDA

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

I1

```          I1 is INTEGER
Index of the first row to swap
```

I2

```          I2 is INTEGER
Index of the second row to swap
```

Author:

Univ. of Tennessee

Univ. of California Berkeley