*> \brief \b ZLASET initializes the off-diagonal elements and the diagonal elements of a matrix to given values. * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * *> \htmlonly *> Download ZLASET + dependencies *> *> [TGZ] *> *> [ZIP] *> *> [TXT] *> \endhtmlonly * * Definition: * =========== * * SUBROUTINE ZLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) * * .. Scalar Arguments .. * CHARACTER UPLO * INTEGER LDA, M, N * COMPLEX*16 ALPHA, BETA * .. * .. Array Arguments .. * COMPLEX*16 A( LDA, * ) * .. * * *> \par Purpose: * ============= *> *> \verbatim *> *> ZLASET initializes a 2-D array A to BETA on the diagonal and *> ALPHA on the offdiagonals. *> \endverbatim * * Arguments: * ========== * *> \param[in] UPLO *> \verbatim *> UPLO is 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. *> \endverbatim *> *> \param[in] M *> \verbatim *> M is INTEGER *> On entry, M specifies the number of rows of A. *> \endverbatim *> *> \param[in] N *> \verbatim *> N is INTEGER *> On entry, N specifies the number of columns of A. *> \endverbatim *> *> \param[in] ALPHA *> \verbatim *> ALPHA is COMPLEX*16 *> All the offdiagonal array elements are set to ALPHA. *> \endverbatim *> *> \param[in] BETA *> \verbatim *> BETA is COMPLEX*16 *> All the diagonal array elements are set to BETA. *> \endverbatim *> *> \param[out] A *> \verbatim *> A is COMPLEX*16 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) *> \endverbatim *> *> \param[in] LDA *> \verbatim *> LDA is INTEGER *> The leading dimension of the array A. LDA >= max(1,M). *> \endverbatim * * Authors: * ======== * *> \author Univ. of Tennessee *> \author Univ. of California Berkeley *> \author Univ. of Colorado Denver *> \author NAG Ltd. * *> \ingroup complex16OTHERauxiliary * * ===================================================================== SUBROUTINE ZLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) * * -- LAPACK auxiliary routine -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- * * .. Scalar Arguments .. CHARACTER UPLO INTEGER LDA, M, N COMPLEX*16 ALPHA, BETA * .. * .. Array Arguments .. COMPLEX*16 A( LDA, * ) * .. * * ===================================================================== * * .. 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 ZLASET * END