Previous: dlascl Up: ../lapack-d.html Next: dlasr

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).