# clapmt.f

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

## SYNOPSIS

### Functions/Subroutines

subroutine clapmt (FORWRD, M, N, X, LDX, K)
CLAPMT performs a forward or backward permutation of the columns of a matrix.

## Function/Subroutine Documentation

### subroutine clapmt (logical FORWRD, integer M, integer N, complex, dimension( ldx, * ) X, integer LDX, integer, dimension( * ) K)

CLAPMT performs a forward or backward permutation of the columns of a matrix.

Purpose:

``` CLAPMT rearranges the columns of the M by N matrix X as specified
by the permutation K(1),K(2),...,K(N) of the integers 1,...,N.
If FORWRD = .TRUE.,  forward permutation:

X(*,K(J)) is moved X(*,J) for J = 1,2,...,N.

If FORWRD = .FALSE., backward permutation:

X(*,J) is moved to X(*,K(J)) for J = 1,2,...,N.
```

Parameters:

FORWRD

```          FORWRD is LOGICAL
= .TRUE., forward permutation
= .FALSE., backward permutation
```

M

```          M is INTEGER
The number of rows of the matrix X. M >= 0.
```

N

```          N is INTEGER
The number of columns of the matrix X. N >= 0.
```

X

```          X is COMPLEX array, dimension (LDX,N)
On entry, the M by N matrix X.
On exit, X contains the permuted matrix X.
```

LDX

```          LDX is INTEGER
The leading dimension of the array X, LDX >= MAX(1,M).
```

K

```          K is INTEGER array, dimension (N)
On entry, K contains the permutation vector. K is used as
internal workspace, but reset to its original value on
output.
```

Author:

Univ. of Tennessee

Univ. of California Berkeley