CHFRK(1)LAPACK routine (version 3.2) CHFRK(1)NAME
CHFRK - 3 BLAS like routine for C in RFP Format
SYNOPSIS
SUBROUTINE CHFRK( TRANSR, UPLO, TRANS, N, K, ALPHA, A, LDA, BETA,
+ C )
REAL ALPHA, BETA
INTEGER K, LDA, N
CHARACTER TRANS, TRANSR, UPLO
COMPLEX A( LDA, * ), C( * )
PURPOSE
Level 3 BLAS like routine for C in RFP Format. CHFRK performs one of
the Hermitian rank--k operations
C := alpha*A*conjg( A' ) + beta*C,
or
C := alpha*conjg( A' )*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.
ARGUMENTS
TRANSR - (input) CHARACTER. = 'N': The Normal Form of RFP A is
stored;
= 'C': The Conjugate-transpose Form of RFP A is stored.
UPLO - (input) CHARACTER.
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 tri‐
angular part of C is to be referenced. Unchanged on exit.
TRANS - (input) CHARACTER.
On entry, TRANS specifies the operation to be performed as
follows: TRANS = 'N' or 'n' C := alpha*A*conjg( A' ) + beta*C.
TRANS = 'C' or 'c' C := alpha*conjg( A' )*A + beta*C.
Unchanged on exit.
N - (input) INTEGER.
On entry, N specifies the order of the matrix C. N must be at
least zero. Unchanged on exit.
K - (input) 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 - (input) REAL.
On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
A - (input) COMPLEX array of 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 - (input) 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 - (input) REAL.
On entry, BETA specifies the scalar beta. Unchanged on exit.
C - (input/output) 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 diago‐
nal elements need not be set, they are assumed to be zero, and
on exit they are set to zero.
ARGUMENTS
LAPACK routine (version 3.2) November 2008 CHFRK(1)
