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Diffstat (limited to 'BLAS/SRC/ssbmv.f')
| -rw-r--r-- | BLAS/SRC/ssbmv.f | 313 |
1 files changed, 195 insertions, 118 deletions
diff --git a/BLAS/SRC/ssbmv.f b/BLAS/SRC/ssbmv.f index 88b4adc1..82f76ceb 100644 --- a/BLAS/SRC/ssbmv.f +++ b/BLAS/SRC/ssbmv.f @@ -1,134 +1,211 @@ - SUBROUTINE SSBMV(UPLO,N,K,ALPHA,A,LDA,X,INCX,BETA,Y,INCY) -* .. Scalar Arguments .. - REAL ALPHA,BETA - INTEGER INCX,INCY,K,LDA,N - CHARACTER UPLO -* .. -* .. Array Arguments .. - REAL A(LDA,*),X(*),Y(*) -* .. +*> \brief \b SSBMV +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ * +* Definition +* ========== +* +* SUBROUTINE SSBMV(UPLO,N,K,ALPHA,A,LDA,X,INCX,BETA,Y,INCY) +* +* .. Scalar Arguments .. +* REAL ALPHA,BETA +* INTEGER INCX,INCY,K,LDA,N +* CHARACTER UPLO +* .. +* .. Array Arguments .. +* REAL A(LDA,*),X(*),Y(*) +* .. +* * Purpose * ======= * -* SSBMV performs the matrix-vector operation +*>\details \b Purpose: +*>\verbatim +*> +*> SSBMV performs the matrix-vector operation +*> +*> y := alpha*A*x + beta*y, +*> +*> where alpha and beta are scalars, x and y are n element vectors and +*> A is an n by n symmetric band matrix, with k super-diagonals. +*> +*>\endverbatim +* +* Arguments +* ========= +* +*> \param[in] UPLO +*> \verbatim +*> UPLO is CHARACTER*1 +*> On entry, UPLO specifies whether the upper or lower +*> triangular part of the band matrix A is being supplied as +*> follows: +*> \endverbatim +*> \verbatim +*> UPLO = 'U' or 'u' The upper triangular part of A is +*> being supplied. +*> \endverbatim +*> \verbatim +*> UPLO = 'L' or 'l' The lower triangular part of A is +*> being supplied. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> On entry, N specifies the order of the matrix A. +*> N must be at least zero. +*> \endverbatim +*> +*> \param[in] K +*> \verbatim +*> K is INTEGER +*> On entry, K specifies the number of super-diagonals of the +*> matrix A. K must satisfy 0 .le. K. +*> \endverbatim +*> +*> \param[in] ALPHA +*> \verbatim +*> ALPHA is REAL +*> On entry, ALPHA specifies the scalar alpha. +*> \endverbatim +*> +*> \param[in] A +*> \verbatim +*> A is REAL array of DIMENSION ( LDA, n ). +*> Before entry with UPLO = 'U' or 'u', the leading ( k + 1 ) +*> by n part of the array A must contain the upper triangular +*> band part of the symmetric matrix, supplied column by +*> column, with the leading diagonal of the matrix in row +*> ( k + 1 ) of the array, the first super-diagonal starting at +*> position 2 in row k, and so on. The top left k by k triangle +*> of the array A is not referenced. +*> The following program segment will transfer the upper +*> triangular part of a symmetric band matrix from conventional +*> full matrix storage to band storage: +*> \endverbatim +*> \verbatim +*> DO 20, J = 1, N +*> M = K + 1 - J +*> DO 10, I = MAX( 1, J - K ), J +*> A( M + I, J ) = matrix( I, J ) +*> 10 CONTINUE +*> 20 CONTINUE +*> \endverbatim +*> \verbatim +*> Before entry with UPLO = 'L' or 'l', the leading ( k + 1 ) +*> by n part of the array A must contain the lower triangular +*> band part of the symmetric matrix, supplied column by +*> column, with the leading diagonal of the matrix in row 1 of +*> the array, the first sub-diagonal starting at position 1 in +*> row 2, and so on. The bottom right k by k triangle of the +*> array A is not referenced. +*> The following program segment will transfer the lower +*> triangular part of a symmetric band matrix from conventional +*> full matrix storage to band storage: +*> \endverbatim +*> \verbatim +*> DO 20, J = 1, N +*> M = 1 - J +*> DO 10, I = J, MIN( N, J + K ) +*> A( M + I, J ) = matrix( I, J ) +*> 10 CONTINUE +*> 20 CONTINUE +*> \endverbatim +*> +*> \param[in] LDA +*> \verbatim +*> LDA is INTEGER +*> On entry, LDA specifies the first dimension of A as declared +*> in the calling (sub) program. LDA must be at least +*> ( k + 1 ). +*> \endverbatim +*> +*> \param[in] X +*> \verbatim +*> X is REAL array of DIMENSION at least +*> ( 1 + ( n - 1 )*abs( INCX ) ). +*> Before entry, the incremented array X must contain the +*> vector x. +*> \endverbatim +*> +*> \param[in] INCX +*> \verbatim +*> INCX is INTEGER +*> On entry, INCX specifies the increment for the elements of +*> X. INCX must not be zero. +*> \endverbatim +*> +*> \param[in] BETA +*> \verbatim +*> BETA is REAL +*> On entry, BETA specifies the scalar beta. +*> \endverbatim +*> +*> \param[in,out] Y +*> \verbatim +*> Y is REAL array of DIMENSION at least +*> ( 1 + ( n - 1 )*abs( INCY ) ). +*> Before entry, the incremented array Y must contain the +*> vector y. On exit, Y is overwritten by the updated vector y. +*> \endverbatim +*> +*> \param[in] INCY +*> \verbatim +*> INCY is INTEGER +*> On entry, INCY specifies the increment for the elements of +*> Y. INCY must not be zero. +*> \endverbatim +*> +* +* Authors +* ======= * -* y := alpha*A*x + beta*y, +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. * -* where alpha and beta are scalars, x and y are n element vectors and -* A is an n by n symmetric band matrix, with k super-diagonals. +*> \date November 2011 * -* Arguments -* ========== +*> \ingroup single_blas_level2 * -* UPLO - CHARACTER*1. -* On entry, UPLO specifies whether the upper or lower -* triangular part of the band matrix A is being supplied as -* follows: -* -* UPLO = 'U' or 'u' The upper triangular part of A is -* being supplied. -* -* UPLO = 'L' or 'l' The lower triangular part of A is -* being supplied. -* -* Unchanged on exit. -* -* N - INTEGER. -* On entry, N specifies the order of the matrix A. -* N must be at least zero. -* Unchanged on exit. -* -* K - INTEGER. -* On entry, K specifies the number of super-diagonals of the -* matrix A. K must satisfy 0 .le. K. -* Unchanged on exit. -* -* ALPHA - REAL . -* On entry, ALPHA specifies the scalar alpha. -* Unchanged on exit. -* -* A - REAL array of DIMENSION ( LDA, n ). -* Before entry with UPLO = 'U' or 'u', the leading ( k + 1 ) -* by n part of the array A must contain the upper triangular -* band part of the symmetric matrix, supplied column by -* column, with the leading diagonal of the matrix in row -* ( k + 1 ) of the array, the first super-diagonal starting at -* position 2 in row k, and so on. The top left k by k triangle -* of the array A is not referenced. -* The following program segment will transfer the upper -* triangular part of a symmetric band matrix from conventional -* full matrix storage to band storage: -* -* DO 20, J = 1, N -* M = K + 1 - J -* DO 10, I = MAX( 1, J - K ), J -* A( M + I, J ) = matrix( I, J ) -* 10 CONTINUE -* 20 CONTINUE -* -* Before entry with UPLO = 'L' or 'l', the leading ( k + 1 ) -* by n part of the array A must contain the lower triangular -* band part of the symmetric matrix, supplied column by -* column, with the leading diagonal of the matrix in row 1 of -* the array, the first sub-diagonal starting at position 1 in -* row 2, and so on. The bottom right k by k triangle of the -* array A is not referenced. -* The following program segment will transfer the lower -* triangular part of a symmetric band matrix from conventional -* full matrix storage to band storage: -* -* DO 20, J = 1, N -* M = 1 - J -* DO 10, I = J, MIN( N, J + K ) -* A( M + I, J ) = matrix( I, J ) -* 10 CONTINUE -* 20 CONTINUE -* -* Unchanged on exit. -* -* LDA - INTEGER. -* On entry, LDA specifies the first dimension of A as declared -* in the calling (sub) program. LDA must be at least -* ( k + 1 ). -* Unchanged on exit. -* -* X - REAL array of DIMENSION at least -* ( 1 + ( n - 1 )*abs( INCX ) ). -* Before entry, the incremented array X must contain the -* vector x. -* Unchanged on exit. -* -* INCX - INTEGER. -* On entry, INCX specifies the increment for the elements of -* X. INCX must not be zero. -* Unchanged on exit. -* -* BETA - REAL . -* On entry, BETA specifies the scalar beta. -* Unchanged on exit. -* -* Y - REAL array of DIMENSION at least -* ( 1 + ( n - 1 )*abs( INCY ) ). -* Before entry, the incremented array Y must contain the -* vector y. On exit, Y is overwritten by the updated vector y. -* -* INCY - INTEGER. -* On entry, INCY specifies the increment for the elements of -* Y. INCY must not be zero. -* Unchanged on exit. * * Further Details * =============== +*>\details \b Further \b Details +*> \verbatim +*> +*> Level 2 Blas routine. +*> The vector and matrix arguments are not referenced when N = 0, or M = 0 +*> +*> -- Written on 22-October-1986. +*> Jack Dongarra, Argonne National Lab. +*> Jeremy Du Croz, Nag Central Office. +*> Sven Hammarling, Nag Central Office. +*> Richard Hanson, Sandia National Labs. +*> +*> \endverbatim +*> +* ===================================================================== + SUBROUTINE SSBMV(UPLO,N,K,ALPHA,A,LDA,X,INCX,BETA,Y,INCY) * -* Level 2 Blas routine. -* The vector and matrix arguments are not referenced when N = 0, or M = 0 +* -- Reference BLAS level2 routine (version 3.4.0) -- +* -- Reference BLAS is a software package provided by Univ. of Tennessee, -- +* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- +* November 2011 * -* -- Written on 22-October-1986. -* Jack Dongarra, Argonne National Lab. -* Jeremy Du Croz, Nag Central Office. -* Sven Hammarling, Nag Central Office. -* Richard Hanson, Sandia National Labs. +* .. Scalar Arguments .. + REAL ALPHA,BETA + INTEGER INCX,INCY,K,LDA,N + CHARACTER UPLO +* .. +* .. Array Arguments .. + REAL A(LDA,*),X(*),Y(*) +* .. * * ===================================================================== * |