---
name: "lacpy"
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/lacpy"
---

# lacpy(3)

lacpy: copy matrix

## NAME

lacpy - lacpy: copy matrix

## SYNOPSIS

### Functions

subroutine **clacpy** (uplo, m, n, a, lda, b, ldb)\
 **CLACPY** copies all or part of one two-dimensional array to another.  subroutine **dlacpy** (uplo, m, n, a, lda, b, ldb)\
 **DLACPY** copies all or part of one two-dimensional array to another.  subroutine **slacpy** (uplo, m, n, a, lda, b, ldb)\
 **SLACPY** copies all or part of one two-dimensional array to another.  subroutine **zlacpy** (uplo, m, n, a, lda, b, ldb)\
 **ZLACPY** copies all or part of one two-dimensional array to another.

## Detailed Description

## Function Documentation

### subroutine clacpy (character uplo, integer m, integer n, complex, dimension( lda, \* ) a, integer lda, complex, dimension( ldb, \* ) b, integer ldb)

**CLACPY** copies all or part of one two-dimensional array to another.

**Purpose:**

```
!>
!> CLACPY copies all or part of a two-dimensional matrix A to another
!> matrix B.
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          Specifies the part of the matrix A to be copied to B.
!>          = 'U':      Upper triangular part
!>          = 'L':      Lower triangular part
!>          Otherwise:  All of the matrix A
!>
```

*M*

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

*N*

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

*A*

```
!>          A is COMPLEX array, dimension (LDA,N)
!>          The m by n matrix A.  If UPLO = 'U', only the upper trapezium
!>          is accessed; if UPLO = 'L', only the lower trapezium is
!>          accessed.
!>
```

*LDA*

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

*B*

```
!>          B is COMPLEX array, dimension (LDB,N)
!>          On exit, B = A in the locations specified by UPLO.
!>
```

*LDB*

```
!>          LDB is INTEGER
!>          The leading dimension of the array B.  LDB >= max(1,M).
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **102** of file **clacpy.f**.

### subroutine dlacpy (character uplo, integer m, integer n, double precision, dimension( lda, \* ) a, integer lda, double precision, dimension( ldb, \* ) b, integer ldb)

**DLACPY** copies all or part of one two-dimensional array to another.

**Purpose:**

```
!>
!> DLACPY copies all or part of a two-dimensional matrix A to another
!> matrix B.
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          Specifies the part of the matrix A to be copied to B.
!>          = 'U':      Upper triangular part
!>          = 'L':      Lower triangular part
!>          Otherwise:  All of the matrix A
!>
```

*M*

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

*N*

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

*A*

```
!>          A is DOUBLE PRECISION array, dimension (LDA,N)
!>          The m by n matrix A.  If UPLO = 'U', only the upper triangle
!>          or trapezoid is accessed; if UPLO = 'L', only the lower
!>          triangle or trapezoid is accessed.
!>
```

*LDA*

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

*B*

```
!>          B is DOUBLE PRECISION array, dimension (LDB,N)
!>          On exit, B = A in the locations specified by UPLO.
!>
```

*LDB*

```
!>          LDB is INTEGER
!>          The leading dimension of the array B.  LDB >= max(1,M).
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **102** of file **dlacpy.f**.

### subroutine slacpy (character uplo, integer m, integer n, real, dimension( lda, \* ) a, integer lda, real, dimension( ldb, \* ) b, integer ldb)

**SLACPY** copies all or part of one two-dimensional array to another.

**Purpose:**

```
!>
!> SLACPY copies all or part of a two-dimensional matrix A to another
!> matrix B.
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          Specifies the part of the matrix A to be copied to B.
!>          = 'U':      Upper triangular part
!>          = 'L':      Lower triangular part
!>          Otherwise:  All of the matrix A
!>
```

*M*

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

*N*

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

*A*

```
!>          A is REAL array, dimension (LDA,N)
!>          The m by n matrix A.  If UPLO = 'U', only the upper triangle
!>          or trapezoid is accessed; if UPLO = 'L', only the lower
!>          triangle or trapezoid is accessed.
!>
```

*LDA*

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

*B*

```
!>          B is REAL array, dimension (LDB,N)
!>          On exit, B = A in the locations specified by UPLO.
!>
```

*LDB*

```
!>          LDB is INTEGER
!>          The leading dimension of the array B.  LDB >= max(1,M).
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **102** of file **slacpy.f**.

### subroutine zlacpy (character uplo, integer m, integer n, complex\*16, dimension( lda, \* ) a, integer lda, complex\*16, dimension( ldb, \* ) b, integer ldb)

**ZLACPY** copies all or part of one two-dimensional array to another.

**Purpose:**

```
!>
!> ZLACPY copies all or part of a two-dimensional matrix A to another
!> matrix B.
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          Specifies the part of the matrix A to be copied to B.
!>          = 'U':      Upper triangular part
!>          = 'L':      Lower triangular part
!>          Otherwise:  All of the matrix A
!>
```

*M*

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

*N*

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

*A*

```
!>          A is COMPLEX*16 array, dimension (LDA,N)
!>          The m by n matrix A.  If UPLO = 'U', only the upper trapezium
!>          is accessed; if UPLO = 'L', only the lower trapezium is
!>          accessed.
!>
```

*LDA*

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

*B*

```
!>          B is COMPLEX*16 array, dimension (LDB,N)
!>          On exit, B = A in the locations specified by UPLO.
!>
```

*LDB*

```
!>          LDB is INTEGER
!>          The leading dimension of the array B.  LDB >= max(1,M).
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **102** of file **zlacpy.f**.

## Author

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