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# dlaset

```
NAME
DLASET - initialize an m-by-n matrix A to BETA on the diago-
nal and ALPHA on the offdiagonals

SYNOPSIS
SUBROUTINE DLASET( UPLO, M, N, ALPHA, BETA, A, LDA )

CHARACTER      UPLO

INTEGER        LDA, M, N

DOUBLE         PRECISION ALPHA, BETA

DOUBLE         PRECISION A( LDA, * )

PURPOSE
DLASET initializes an m-by-n matrix A to BETA on the diago-
nal 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 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       (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) DOUBLE PRECISION
The constant to which the offdiagonal elements are
to be set.

BETA    (input) DOUBLE PRECISION
The constant to which the diagonal elements are to
be set.

A       (input/output) DOUBLE PRECISION 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).
```