slaset(3)

NAME

SLASET - initialize an m-by-n matrix A to BETA on the di

agonal and ALPHA on the offdiagonals

SYNOPSIS

SUBROUTINE SLASET( UPLO, M, N, ALPHA, BETA, A, LDA )
    CHARACTER      UPLO
    INTEGER        LDA, M, N
    REAL           ALPHA, BETA
    REAL           A( LDA, * )

PURPOSE

SLASET initializes an m-by-n matrix A to BETA on the diag

onal and ALPHA on the offdiagonals.

ARGUMENTS

UPLO (input) CHARACTER*1

Specifies the part of the matrix A to be set. =

'U': Upper triangular part is set; the strictly lower trian

gular 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 (input) INTEGER

The number of rows of the matrix A. M >= 0.

N (input) INTEGER

The number of columns of the matrix A. N >= 0.

ALPHA (input) REAL

The constant to which the offdiagonal elements are

to be set.

BETA (input) REAL

The constant to which the diagonal elements are to

be set.

A (input/output) 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 (input) INTEGER

The leading dimension of the array A. LDA >=

max(1,M).

LAPACK version 3.0 15 June 2000

SLASET(3)