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Diffstat (limited to 'src/fortran/lapack/zlaset.f')
-rw-r--r-- | src/fortran/lapack/zlaset.f | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/src/fortran/lapack/zlaset.f b/src/fortran/lapack/zlaset.f new file mode 100644 index 0000000..88fc21b --- /dev/null +++ b/src/fortran/lapack/zlaset.f @@ -0,0 +1,114 @@ + SUBROUTINE ZLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) +* +* -- LAPACK auxiliary routine (version 3.1) -- +* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. +* November 2006 +* +* .. Scalar Arguments .. + CHARACTER UPLO + INTEGER LDA, M, N + COMPLEX*16 ALPHA, BETA +* .. +* .. Array Arguments .. + COMPLEX*16 A( LDA, * ) +* .. +* +* Purpose +* ======= +* +* ZLASET 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*16 +* All the offdiagonal array elements are set to ALPHA. +* +* BETA (input) COMPLEX*16 +* All the diagonal array elements are set to BETA. +* +* A (input/output) 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) +* +* 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 ZLASET +* + END |