# zhemm.f (3) - Linux Manuals

zhemm.f -

## SYNOPSIS

### Functions/Subroutines

subroutine zhemm (SIDE, UPLO, M, N, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
ZHEMM

## Function/Subroutine Documentation

### subroutine zhemm (characterSIDE, characterUPLO, integerM, integerN, complex*16ALPHA, complex*16, dimension(lda,*)A, integerLDA, complex*16, dimension(ldb,*)B, integerLDB, complex*16BETA, complex*16, dimension(ldc,*)C, integerLDC)

ZHEMM Purpose:

``` ZHEMM  performs one of the matrix-matrix operations

C := alpha*A*B + beta*C,

or

C := alpha*B*A + beta*C,

where alpha and beta are scalars, A is an hermitian matrix and  B and
C are m by n matrices.
```

Parameters:

SIDE

```          SIDE is CHARACTER*1
On entry,  SIDE  specifies whether  the  hermitian matrix  A
appears on the  left or right  in the  operation as follows:

SIDE = 'L' or 'l'   C := alpha*A*B + beta*C,

SIDE = 'R' or 'r'   C := alpha*B*A + beta*C,
```

UPLO

```          UPLO is CHARACTER*1
On  entry,   UPLO  specifies  whether  the  upper  or  lower
triangular  part  of  the  hermitian  matrix   A  is  to  be
referenced as follows:

UPLO = 'U' or 'u'   Only the upper triangular part of the
hermitian matrix is to be referenced.

UPLO = 'L' or 'l'   Only the lower triangular part of the
hermitian matrix is to be referenced.
```

M

```          M is INTEGER
On entry,  M  specifies the number of rows of the matrix  C.
M  must be at least zero.
```

N

```          N is INTEGER
On entry, N specifies the number of columns of the matrix C.
N  must be at least zero.
```

ALPHA

```          ALPHA is COMPLEX*16
On entry, ALPHA specifies the scalar alpha.
```

A

```          A is COMPLEX*16 array of DIMENSION ( LDA, ka ), where ka is
m  when  SIDE = 'L' or 'l'  and is n  otherwise.
Before entry  with  SIDE = 'L' or 'l',  the  m by m  part of
the array  A  must contain the  hermitian matrix,  such that
when  UPLO = 'U' or 'u', the leading m by m upper triangular
part of the array  A  must contain the upper triangular part
of the  hermitian matrix and the  strictly  lower triangular
part of  A  is not referenced,  and when  UPLO = 'L' or 'l',
the leading  m by m  lower triangular part  of the  array  A
must  contain  the  lower triangular part  of the  hermitian
matrix and the  strictly upper triangular part of  A  is not
referenced.
Before entry  with  SIDE = 'R' or 'r',  the  n by n  part of
the array  A  must contain the  hermitian matrix,  such that
when  UPLO = 'U' or 'u', the leading n by n upper triangular
part of the array  A  must contain the upper triangular part
of the  hermitian matrix and the  strictly  lower triangular
part of  A  is not referenced,  and when  UPLO = 'L' or 'l',
the leading  n by n  lower triangular part  of the  array  A
must  contain  the  lower triangular part  of the  hermitian
matrix and the  strictly upper triangular part of  A  is not
referenced.
Note that the imaginary parts  of the diagonal elements need
not be set, they are assumed to be zero.
```

LDA

```          LDA is INTEGER
On entry, LDA specifies the first dimension of A as declared
in the  calling (sub) program. When  SIDE = 'L' or 'l'  then
LDA must be at least  max( 1, m ), otherwise  LDA must be at
least max( 1, n ).
```

B

```          B is COMPLEX*16 array of DIMENSION ( LDB, n ).
Before entry, the leading  m by n part of the array  B  must
contain the matrix B.
```

LDB

```          LDB is INTEGER
On entry, LDB specifies the first dimension of B as declared
in  the  calling  (sub)  program.   LDB  must  be  at  least
max( 1, m ).
```

BETA

```          BETA is COMPLEX*16
On entry,  BETA  specifies the scalar  beta.  When  BETA  is
supplied as zero then C need not be set on input.
```

C

```          C is COMPLEX*16 array of DIMENSION ( LDC, n ).
Before entry, the leading  m by n  part of the array  C must
contain the matrix  C,  except when  beta  is zero, in which
case C need not be set on entry.
On exit, the array  C  is overwritten by the  m by n updated
matrix.
```

LDC

```          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, m ).
```

Author:

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Date:

November 2011

Further Details:

```  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.
```

Definition at line 192 of file zhemm.f.

## Author

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