chfrk.f3
Usage
Functions/Subroutines
subroutine chfrk (transr, uplo, trans, n, k, alpha, a, lda, beta, c)
CHFRK performs a Hermitian rank-k operation for matrix in RFP format.
Function/Subroutine Documentation
subroutine chfrk (character transr, character uplo, character trans, integer n, integer k, real alpha, complex, dimension( lda, * ) a, integer lda, real beta, complex, dimension( * ) c)
CHFRK performs a Hermitian rank-k operation for matrix in RFP format.
Purpose:
!> !> Level 3 BLAS like routine for C in RFP Format. !> !> CHFRK 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
TRANSR
!> TRANSR is CHARACTER*1 !> = 'N': The Normal Form of RFP A is stored; !> = 'C': The Conjugate-transpose Form of RFP A is stored. !>
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. !> !> Unchanged on exit. !>
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. !> !> Unchanged on exit. !>
N
!> N is INTEGER !> On entry, N specifies the order of the matrix C. N must be !> at least zero. !> Unchanged on exit. !>
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. !> Unchanged on exit. !>
ALPHA
!> ALPHA is REAL !> On entry, ALPHA specifies the scalar alpha. !> Unchanged on exit. !>
A
!> A is COMPLEX 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. !> Unchanged on exit. !>
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 ). !> Unchanged on exit. !>
BETA
!> BETA is REAL !> On entry, BETA specifies the scalar beta. !> Unchanged on exit. !>
C
!> C is COMPLEX array, dimension (N*(N+1)/2) !> On entry, the matrix A in RFP Format. RFP Format is !> described by TRANSR, UPLO and N. 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. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 166 of file chfrk.f.
Releases
4 releases since Debian 7 (Wheezy); the text changed 3 times.