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Diffstat (limited to '2.3-1/src/fortran/lapack/dlaset.f')
| -rw-r--r-- | 2.3-1/src/fortran/lapack/dlaset.f | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/2.3-1/src/fortran/lapack/dlaset.f b/2.3-1/src/fortran/lapack/dlaset.f new file mode 100644 index 00000000..fc7bc2f5 --- /dev/null +++ b/2.3-1/src/fortran/lapack/dlaset.f @@ -0,0 +1,114 @@ + SUBROUTINE DLASET( 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 + DOUBLE PRECISION ALPHA, BETA +* .. +* .. Array Arguments .. + DOUBLE PRECISION A( LDA, * ) +* .. +* +* Purpose +* ======= +* +* DLASET initializes an m-by-n matrix 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 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). +* +* ===================================================================== +* +* .. Local Scalars .. + INTEGER I, J +* .. +* .. External Functions .. + LOGICAL LSAME + EXTERNAL LSAME +* .. +* .. Intrinsic Functions .. + INTRINSIC MIN +* .. +* .. Executable Statements .. +* + IF( LSAME( UPLO, 'U' ) ) THEN +* +* Set the strictly upper triangular or trapezoidal 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 +* + ELSE IF( LSAME( UPLO, 'L' ) ) THEN +* +* Set the strictly lower triangular or trapezoidal part of the +* array to ALPHA. +* + DO 40 J = 1, MIN( M, N ) + DO 30 I = J + 1, M + A( I, J ) = ALPHA + 30 CONTINUE + 40 CONTINUE +* + ELSE +* +* Set the leading m-by-n submatrix to ALPHA. +* + DO 60 J = 1, N + DO 50 I = 1, M + A( I, J ) = ALPHA + 50 CONTINUE + 60 CONTINUE + END IF +* +* Set the first min(M,N) diagonal elements to BETA. +* + DO 70 I = 1, MIN( M, N ) + A( I, I ) = BETA + 70 CONTINUE +* + RETURN +* +* End of DLASET +* + END |