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

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

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

          ALPHA is DOUBLE PRECISION
          The constant to which the offdiagonal elements are to be set.

          BETA is DOUBLE PRECISION
          The constant to which the diagonal elements are to be set.

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