BLAS/SRC/zhbmv.f(3) Library Functions Manual BLAS/SRC/zhbmv.f(3) NAME BLAS/SRC/zhbmv.f SYNOPSIS Functions/Subroutines subroutine zhbmv (uplo, n, k, alpha, a, lda, x, incx, beta, y, incy) ZHBMV Function/Subroutine Documentation subroutine zhbmv (character uplo, integer n, integer k, complex*16 alpha, complex*16, dimension(lda,*) a, integer lda, complex*16, dimension(*) x, integer incx, complex*16 beta, complex*16, dimension(*) y, integer incy) ZHBMV Purpose: !> !> ZHBMV 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 hermitian band matrix, with k super-diagonals. !> Parameters UPLO !> 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: !> !> 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. !> N !> N is INTEGER !> On entry, N specifies the order of the matrix A. !> N must be at least zero. !> K !> K is INTEGER !> On entry, K specifies the number of super-diagonals of the !> matrix A. K must satisfy 0 .le. K. !> ALPHA !> ALPHA is COMPLEX*16 !> On entry, ALPHA specifies the scalar alpha. !> A !> A is COMPLEX*16 array, 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 hermitian 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 hermitian 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 hermitian 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 hermitian 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 !> !> Note that the imaginary parts of the diagonal elements need !> not be set and are assumed to be zero. !> LDA !> 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 ). !> X !> X is COMPLEX*16 array, dimension at least !> ( 1 + ( n - 1 )*abs( INCX ) ). !> Before entry, the incremented array X must contain the !> vector x. !> INCX !> INCX is INTEGER !> On entry, INCX specifies the increment for the elements of !> X. INCX must not be zero. !> BETA !> BETA is COMPLEX*16 !> On entry, BETA specifies the scalar beta. !> Y !> Y is COMPLEX*16 array, 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 !> INCY is INTEGER !> On entry, INCY specifies the increment for the elements of !> Y. INCY must not be zero. !> Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Further Details: !> !> 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. !> Definition at line 186 of file zhbmv.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 BLAS/SRC/zhbmv.f(3)