.TH "BLAS/SRC/zherk.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
BLAS/SRC/zherk.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBzherk\fP (uplo, trans, n, k, alpha, a, lda, beta, c, ldc)"
.br
.RI "\fBZHERK\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine zherk (character uplo, character trans, integer n, integer k, double precision alpha, complex*16, dimension(lda,*) a, integer lda, double precision beta, complex*16, dimension(ldc,*) c, integer ldc)"

.PP
\fBZHERK\fP 
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
!>
!> ZHERK  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\&.
!> 
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIUPLO\fP 
.PP
.nf
!>          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\&.
!> 
.fi
.PP
.br
\fITRANS\fP 
.PP
.nf
!>          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\&.
!> 
.fi
.PP
.br
\fIN\fP 
.PP
.nf
!>          N is INTEGER
!>           On entry,  N specifies the order of the matrix C\&.  N must be
!>           at least zero\&.
!> 
.fi
.PP
.br
\fIK\fP 
.PP
.nf
!>          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\&.
!> 
.fi
.PP
.br
\fIALPHA\fP 
.PP
.nf
!>          ALPHA is DOUBLE PRECISION \&.
!>           On entry, ALPHA specifies the scalar alpha\&.
!> 
.fi
.PP
.br
\fIA\fP 
.PP
.nf
!>          A is COMPLEX*16 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\&.
!> 
.fi
.PP
.br
\fILDA\fP 
.PP
.nf
!>          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 )\&.
!> 
.fi
.PP
.br
\fIBETA\fP 
.PP
.nf
!>          BETA is DOUBLE PRECISION\&.
!>           On entry, BETA specifies the scalar beta\&.
!> 
.fi
.PP
.br
\fIC\fP 
.PP
.nf
!>          C is COMPLEX*16 array, dimension ( LDC, N )
!>           Before entry  with  UPLO = 'U' or 'u',  the leading  n by n
!>           upper triangular part of the array C must contain the upper
!>           triangular part  of the  hermitian matrix  and the strictly
!>           lower triangular part of C is not referenced\&.  On exit, the
!>           upper triangular part of the array  C is overwritten by the
!>           upper triangular part of the updated matrix\&.
!>           Before entry  with  UPLO = 'L' or 'l',  the leading  n by n
!>           lower triangular part of the array C must contain the lower
!>           triangular part  of the  hermitian matrix  and the strictly
!>           upper triangular part of C is not referenced\&.  On exit, the
!>           lower triangular part of the array  C is overwritten by the
!>           lower triangular part of the updated matrix\&.
!>           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\&.
!> 
.fi
.PP
.br
\fILDC\fP 
.PP
.nf
!>          LDC is INTEGER
!>           On entry, LDC specifies the first dimension of C as declared
!>           in  the  calling  (sub)  program\&.   LDC  must  be  at  least
!>           max( 1, n )\&.
!> 
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 

.PP
Univ\&. of California Berkeley 

.PP
Univ\&. of Colorado Denver 

.PP
NAG Ltd\&. 
.RE
.PP
\fBFurther Details:\fP
.RS 4

.PP
.nf
!>
!>  Level 3 Blas routine\&.
!>
!>  -- Written on 8-February-1989\&.
!>     Jack Dongarra, Argonne National Laboratory\&.
!>     Iain Duff, AERE Harwell\&.
!>     Jeremy Du Croz, Numerical Algorithms Group Ltd\&.
!>     Sven Hammarling, Numerical Algorithms Group Ltd\&.
!>
!>  -- Modified 8-Nov-93 to set C(J,J) to DBLE( C(J,J) ) when BETA = 1\&.
!>     Ed Anderson, Cray Research Inc\&.
!> 
.fi
.PP
 
.RE
.PP

.PP
Definition at line \fB172\fP of file \fBzherk\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.