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## slaset()

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.

Download SLASET + dependencies [TGZ] [ZIP] [TXT]

Purpose:

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

Parameters

  [in]

  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.
      !>

  [in]

  M

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

  [in]

  N

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

  [in]

  ALPHA

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

  [in]

  BETA

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

  [out]

  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).
      !>

  [in]

  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.