chfrk.f man page

subroutine chfrk (TRANSR, UPLO, TRANS, N, K, ALPHA, A, LDA, BETA, C)
CHFRK performs a Hermitian rank-k operation for matrix in RFP format.

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.

Date:

December 2016

Definition at line 170 of file chfrk.f.