---
name: "clapmt.f"
section: "3"
platform: "linux"
package: "lapack-doc"
version: "3.12.1-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/clapmt.f"
---

# clapmt.f(3)

## NAME

SRC/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

Univ. of Colorado Denver

NAG Ltd.

Definition at line **103** of file **clapmt.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.