LAPACK
3.6.1
LAPACK: Linear Algebra PACKage
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subroutine zspmv | ( | character | UPLO, |
integer | N, | ||
complex*16 | ALPHA, | ||
complex*16, dimension( * ) | AP, | ||
complex*16, dimension( * ) | X, | ||
integer | INCX, | ||
complex*16 | BETA, | ||
complex*16, dimension( * ) | Y, | ||
integer | INCY | ||
) |
ZSPMV computes a matrix-vector product for complex vectors using a complex symmetric packed matrix
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ZSPMV 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 matrix, supplied in packed form.
[in] | UPLO | UPLO is CHARACTER*1 On entry, UPLO specifies whether the upper or lower triangular part of the matrix A is supplied in the packed array AP as follows: UPLO = 'U' or 'u' The upper triangular part of A is supplied in AP. UPLO = 'L' or 'l' The lower triangular part of A is supplied in AP. Unchanged on exit. |
[in] | N | N is INTEGER On entry, N specifies the order of the matrix A. N must be at least zero. Unchanged on exit. |
[in] | ALPHA | ALPHA is COMPLEX*16 On entry, ALPHA specifies the scalar alpha. Unchanged on exit. |
[in] | AP | AP is COMPLEX*16 array, dimension at least ( ( N*( N + 1 ) )/2 ). Before entry, with UPLO = 'U' or 'u', the array AP must contain the upper triangular part of the symmetric matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 ) and a( 2, 2 ) respectively, and so on. Before entry, with UPLO = 'L' or 'l', the array AP must contain the lower triangular part of the symmetric matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 ) and a( 3, 1 ) respectively, and so on. Unchanged on exit. |
[in] | X | X is COMPLEX*16 array, dimension at least ( 1 + ( N - 1 )*abs( INCX ) ). Before entry, the incremented array X must contain the N- element vector x. Unchanged on exit. |
[in] | INCX | INCX is INTEGER On entry, INCX specifies the increment for the elements of X. INCX must not be zero. Unchanged on exit. |
[in] | BETA | BETA is COMPLEX*16 On entry, BETA specifies the scalar beta. When BETA is supplied as zero then Y need not be set on input. Unchanged on exit. |
[in,out] | Y | Y is COMPLEX*16 array, dimension at least ( 1 + ( N - 1 )*abs( INCY ) ). Before entry, the incremented array Y must contain the n element vector y. On exit, Y is overwritten by the updated vector y. |
[in] | INCY | INCY is INTEGER On entry, INCY specifies the increment for the elements of Y. INCY must not be zero. Unchanged on exit. |
Definition at line 153 of file zspmv.f.