BLAS/SRC/zherk.f(3) Library Functions Manual BLAS/SRC/zherk.f(3) NAME BLAS/SRC/zherk.f SYNOPSIS Functions/Subroutines subroutine zherk (uplo, trans, n, k, alpha, a, lda, beta, c, ldc) ZHERK Function/Subroutine Documentation subroutine zherk (character uplo, character trans, integer n, integer k, double precision alpha, complex*16, dimension(lda,*) a, integer lda, double precision beta, complex*16, dimension(ldc,*) c, integer ldc) ZHERK Purpose: !> !> ZHERK performs one of the hermitian rank k operations !> !> C := alpha*A*A**H + beta*C, !> !> or !> !> C := alpha*A**H*A + beta*C, !> !> where alpha and beta are real scalars, C is an n by n hermitian !> matrix and A is an n by k matrix in the first case and a k by n !> matrix in the second case. !> Parameters UPLO !> UPLO is CHARACTER*1 !> On entry, UPLO specifies whether the upper or lower !> triangular part of the array C is to be referenced as !> follows: !> !> UPLO = 'U' or 'u' Only the upper triangular part of C !> is to be referenced. !> !> UPLO = 'L' or 'l' Only the lower triangular part of C !> is to be referenced. !> TRANS !> TRANS is CHARACTER*1 !> On entry, TRANS specifies the operation to be performed as !> follows: !> !> TRANS = 'N' or 'n' C := alpha*A*A**H + beta*C. !> !> TRANS = 'C' or 'c' C := alpha*A**H*A + beta*C. !> N !> N is INTEGER !> On entry, N specifies the order of the matrix C. N must be !> at least zero. !> K !> K is INTEGER !> On entry with TRANS = 'N' or 'n', K specifies the number !> of columns of the matrix A, and on entry with !> TRANS = 'C' or 'c', K specifies the number of rows of the !> matrix A. K must be at least zero. !> ALPHA !> ALPHA is DOUBLE PRECISION . !> On entry, ALPHA specifies the scalar alpha. !> A !> A is COMPLEX*16 array, dimension ( LDA, ka ), where ka is !> k when TRANS = 'N' or 'n', and is n otherwise. !> Before entry with TRANS = 'N' or 'n', the leading n by k !> part of the array A must contain the matrix A, otherwise !> the leading k by n part of the array A must contain the !> matrix A. !> LDA !> LDA is INTEGER !> On entry, LDA specifies the first dimension of A as declared !> in the calling (sub) program. When TRANS = 'N' or 'n' !> then LDA must be at least max( 1, n ), otherwise LDA must !> be at least max( 1, k ). !> BETA !> BETA is DOUBLE PRECISION. !> On entry, BETA specifies the scalar beta. !> C !> C is COMPLEX*16 array, dimension ( LDC, N ) !> Before entry with UPLO = 'U' or 'u', the leading n by n !> upper triangular part of the array C must contain the upper !> triangular part of the hermitian matrix and the strictly !> lower triangular part of C is not referenced. On exit, the !> upper triangular part of the array C is overwritten by the !> upper triangular part of the updated matrix. !> Before entry with UPLO = 'L' or 'l', the leading n by n !> lower triangular part of the array C must contain the lower !> triangular part of the hermitian matrix and the strictly !> upper triangular part of C is not referenced. On exit, the !> lower triangular part of the array C is overwritten by the !> lower triangular part of the updated matrix. !> Note that the imaginary parts of the diagonal elements need !> not be set, they are assumed to be zero, and on exit they !> are set to zero. !> LDC !> LDC is INTEGER !> On entry, LDC specifies the first dimension of C as declared !> in the calling (sub) program. LDC must be at least !> max( 1, n ). !> Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Further Details: !> !> Level 3 Blas routine. !> !> -- Written on 8-February-1989. !> Jack Dongarra, Argonne National Laboratory. !> Iain Duff, AERE Harwell. !> Jeremy Du Croz, Numerical Algorithms Group Ltd. !> Sven Hammarling, Numerical Algorithms Group Ltd. !> !> -- Modified 8-Nov-93 to set C(J,J) to DBLE( C(J,J) ) when BETA = 1. !> Ed Anderson, Cray Research Inc. !> Definition at line 172 of file zherk.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 BLAS/SRC/zherk.f(3)