CHFRK
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.
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.
Arguments
| TRANSR |
(input) CHARACTER*1
= 'N': The Normal Form of RFP A is stored;
= 'C': The Conjugate-transpose Form of RFP A is stored. |
| UPLO |
(input) 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 |
(input) 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 |
(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, 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 diagonal elements need not be set, they are assumed to be zero, and on exit they are set to zero. |