CHFRK(3)       LAPACK routine of NEC Numeric Library Collection       CHFRK(3)



NAME
       CHFRK

SYNOPSIS
       SUBROUTINE CHFRK (TRANSR, UPLO, TRANS, N, K, ALPHA, A, LDA, BETA, C)



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.




ARGUMENTS
           TRANSR    (input)
                     TRANSR is CHARACTER*1
                     = 'N':  The Normal Form of RFP A is stored;
                     = 'C':  The Conjugate-transpose Form of RFP A is stored.

           UPLO      (input)
                     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     (input)
                     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         (input)
                     N is INTEGER
                      On entry,  N specifies the order of the matrix C.  N must be
                      at least zero.
                      Unchanged on exit.

           K         (input)
                     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     (input)
                     ALPHA is REAL
                      On entry, ALPHA specifies the scalar alpha.
                      Unchanged on exit.

           A         (input)
                     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       (input)
                     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      (input)
                     BETA is REAL
                      On entry, BETA specifies the scalar beta.
                      Unchanged on exit.

           C         (input/output)
                     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.



LAPACK routine                  31 October 2017                       CHFRK(3)