SUBROUTINE CLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) * * -- LAPACK auxiliary routine (version 3.0) -- * Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., * Courant Institute, Argonne National Lab, and Rice University * October 31, 1992 * * .. Scalar Arguments .. CHARACTER UPLO INTEGER LDA, M, N COMPLEX ALPHA, BETA * .. * .. Array Arguments .. COMPLEX A( LDA, * ) * .. * * Purpose * ======= * * CLASET initializes a 2-D array A to BETA on the diagonal 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 lower triangle * is unchanged. * = 'L': Lower triangular part is set. The upper triangle * is unchanged. * Otherwise: All of the matrix A is set. * * M (input) INTEGER * On entry, M specifies the number of rows of A. * * N (input) INTEGER * On entry, N specifies the number of columns of A. * * ALPHA (input) COMPLEX * All the offdiagonal array elements are set to ALPHA. * * BETA (input) COMPLEX * All the diagonal array elements are set to BETA. * * A (input/output) COMPLEX array, dimension (LDA,N) * On entry, the m by n matrix A. * On exit, A(i,j) = ALPHA, 1 <= i <= m, 1 <= j <= n, i.ne.j; * A(i,i) = BETA , 1 <= i <= min(m,n) * * LDA (input) INTEGER * The leading dimension of the array A. LDA >= max(1,M). * * ===================================================================== * * .. Local Scalars .. INTEGER I, J * .. * .. External Functions .. LOGICAL LSAME EXTERNAL LSAME * .. * .. Intrinsic Functions .. INTRINSIC MIN * .. * .. Executable Statements .. * IF( LSAME( UPLO, 'U' ) ) THEN * * Set the diagonal to BETA and the strictly upper triangular * part of the array to ALPHA. * DO 20 J = 2, N DO 10 I = 1, MIN( J-1, M ) A( I, J ) = ALPHA 10 CONTINUE 20 CONTINUE DO 30 I = 1, MIN( N, M ) A( I, I ) = BETA 30 CONTINUE * ELSE IF( LSAME( UPLO, 'L' ) ) THEN * * Set the diagonal to BETA and the strictly lower triangular * part of the array to ALPHA. * DO 50 J = 1, MIN( M, N ) DO 40 I = J + 1, M A( I, J ) = ALPHA 40 CONTINUE 50 CONTINUE DO 60 I = 1, MIN( N, M ) A( I, I ) = BETA 60 CONTINUE * ELSE * * Set the array to BETA on the diagonal and ALPHA on the * offdiagonal. * DO 80 J = 1, N DO 70 I = 1, M A( I, J ) = ALPHA 70 CONTINUE 80 CONTINUE DO 90 I = 1, MIN( M, N ) A( I, I ) = BETA 90 CONTINUE END IF * RETURN * * End of CLASET * END