# cgemv.f(3) [centos man page]

```cgemv.f(3)							      LAPACK								cgemv.f(3)

NAME
cgemv.f -

SYNOPSIS
Functions/Subroutines
subroutine cgemv (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
CGEMV

Function/Subroutine Documentation
subroutine cgemv (characterTRANS, integerM, integerN, complexALPHA, complex, dimension(lda,*)A, integerLDA, complex, dimension(*)X,
integerINCX, complexBETA, complex, dimension(*)Y, integerINCY)
CGEMV Purpose:

CGEMV performs one of the matrix-vector operations

y := alpha*A*x + beta*y,   or   y := alpha*A**T*x + beta*y,   or

y := alpha*A**H*x + beta*y,

where alpha and beta are scalars, x and y are vectors and A is an
m by n matrix.

Parameters:
TRANS

TRANS is CHARACTER*1
On entry, TRANS specifies the operation to be performed as
follows:

TRANS = 'N' or 'n'   y := alpha*A*x + beta*y.

TRANS = 'T' or 't'   y := alpha*A**T*x + beta*y.

TRANS = 'C' or 'c'   y := alpha*A**H*x + beta*y.

M

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

N

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

ALPHA

ALPHA is COMPLEX
On entry, ALPHA specifies the scalar alpha.

A

A is COMPLEX array of DIMENSION ( LDA, n ).
Before entry, the leading m by n part of the array A must
contain the matrix of coefficients.

LDA

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

X

X is COMPLEX array of DIMENSION at least
( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n'
and at least
( 1 + ( m - 1 )*abs( INCX ) ) otherwise.
Before entry, the incremented array X must contain the
vector x.

INCX

INCX is INTEGER
On entry, INCX specifies the increment for the elements of
X. INCX must not be zero.

BETA

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

Y

Y is COMPLEX array of DIMENSION at least
( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n'
and at least
( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
Before entry with BETA non-zero, the incremented array Y
must contain the vector y. On exit, Y is overwritten by the
updated vector y.

INCY

INCY is INTEGER
On entry, INCY specifies the increment for the elements of
Y. INCY must not be zero.

Author:
Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Date:
November 2011

Further Details:

Level 2 Blas routine.
The vector and matrix arguments are not referenced when N = 0, or M = 0

-- Written on 22-October-1986.
Jack Dongarra, Argonne National Lab.
Jeremy Du Croz, Nag Central Office.
Sven Hammarling, Nag Central Office.
Richard Hanson, Sandia National Labs.

Definition at line 159 of file cgemv.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012							cgemv.f(3)```

## Check Out this Related Man Page

```CGEMV(l)							   BLAS routine 							  CGEMV(l)

NAME
CGEMV - perform one of the matrix-vector operations   y := alpha*A*x + beta*y, or y := alpha*A'*x + beta*y, or	y := alpha*conjg( A' )*x +
beta*y,

SYNOPSIS
SUBROUTINE CGEMV ( TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY )

COMPLEX	ALPHA, BETA

INTEGER	INCX, INCY, LDA, M, N

CHARACTER*1	TRANS

COMPLEX	A( LDA, * ), X( * ), Y( * )

PURPOSE
CGEMV  performs one of the matrix-vector operations

where alpha and beta are scalars, x and y are vectors and A is an m by n matrix.

PARAMETERS
TRANS  - CHARACTER*1.
On entry, TRANS specifies the operation to be performed as follows:

TRANS = 'N' or 'n'   y := alpha*A*x + beta*y.

TRANS = 'T' or 't'   y := alpha*A'*x + beta*y.

TRANS = 'C' or 'c'   y := alpha*conjg( A' )*x + beta*y.

Unchanged on exit.

M      - INTEGER.
On entry, M specifies the number of rows of the matrix A.  M must be at least zero.  Unchanged on exit.

N      - INTEGER.
On entry, N specifies the number of columns of the matrix A.  N must be at least zero.  Unchanged on exit.

ALPHA  - COMPLEX 	.
On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

A      - COMPLEX 	 array of DIMENSION ( LDA, n ).
Before entry, the leading m by n part of the array A must contain the matrix of coefficients.  Unchanged on exit.

LDA    - INTEGER.
On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. LDA  must  be	at  least  max(  1,  m	).
Unchanged on exit.

X      - COMPLEX 	 array of DIMENSION at least
(  1  +  (  n  -	1 )*abs( INCX ) ) when TRANS = 'N' or 'n' and at least ( 1 + ( m - 1 )*abs( INCX ) ) otherwise.  Before entry, the
incremented array X must contain the vector x.  Unchanged on exit.

INCX   - INTEGER.
On entry, INCX specifies the increment for the elements of X. INCX must not be zero.  Unchanged on exit.

BETA   - COMPLEX 	.
On entry, BETA specifies the scalar beta. When BETA is supplied as zero then Y need not be set on input.	Unchanged on exit.

Y      - COMPLEX 	 array of DIMENSION at least
( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n' and at least ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.  Before entry with  BETA
non-zero, the incremented array Y must contain the vector y. On exit, Y is overwritten by the updated vector y.

INCY   - INTEGER.
On entry, INCY specifies the increment for the elements of Y. INCY must not be zero.  Unchanged on exit.

Level 2 Blas routine.

-- Written on 22-October-1986.  Jack Dongarra, Argonne National Lab.  Jeremy Du Croz, Nag Central Office.  Sven Hammarling, Nag Cen-
tral Office.  Richard Hanson, Sandia National Labs.

BLAS routine							  16 October 1992							  CGEMV(l)```
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