---
name: "slaset.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/slaset.f"
---

# slaset.f(3)

## NAME

SRC/slaset.f

## SYNOPSIS

### Functions/Subroutines

subroutine **slaset** (uplo, m, n, alpha, beta, a, lda)\
 **SLASET** initializes the off-diagonal elements and the diagonal elements of a matrix to given values.

## Function/Subroutine Documentation

### subroutine slaset (character uplo, integer m, integer n, real alpha, real beta, real, dimension( lda, \* ) a, integer lda)

**SLASET** initializes the off-diagonal elements and the diagonal elements of a matrix to given values.

**Purpose:**

```
!>
!> SLASET initializes an m-by-n matrix A to BETA on the diagonal and
!> ALPHA on the offdiagonals.
!>
```

**Parameters**

*UPLO*

```
!>          UPLO is CHARACTER*1
!>          Specifies the part of the matrix A to be set.
!>          = 'U':      Upper triangular part is set; the strictly lower
!>                      triangular part of A is not changed.
!>          = 'L':      Lower triangular part is set; the strictly upper
!>                      triangular part of A is not changed.
!>          Otherwise:  All of the matrix A is set.
!>
```

*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.
!>
```

*ALPHA*

```
!>          ALPHA is REAL
!>          The constant to which the offdiagonal elements are to be set.
!>
```

*BETA*

```
!>          BETA is REAL
!>          The constant to which the diagonal elements are to be set.
!>
```

*A*

```
!>          A is REAL array, dimension (LDA,N)
!>          On exit, the leading m-by-n submatrix of A is set as follows:
!>
!>          if UPLO = 'U', A(i,j) = ALPHA, 1<=i<=j-1, 1<=j<=n,
!>          if UPLO = 'L', A(i,j) = ALPHA, j+1<=i<=m, 1<=j<=n,
!>          otherwise,     A(i,j) = ALPHA, 1<=i<=m, 1<=j<=n, i.ne.j,
!>
!>          and, for all UPLO, A(i,i) = BETA, 1<=i<=min(m,n).
!>
```

*LDA*

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

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **109** of file **slaset.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.