p?geadd

Performs sum operation for two distributed general matrices.

Syntax

call psgeadd(trans, m, n, alpha, a, ia, ja, desca, beta, c, ic, jc, descc)

call pdgeadd(trans, m, n, alpha, a, ia, ja, desca, beta, c, ic, jc, descc)

call pcgeadd(trans, m, n, alpha, a, ia, ja, desca, beta, c, ic, jc, descc)

call pzgeadd(trans, m, n, alpha, a, ia, ja, desca, beta, c, ic, jc, descc)

Include Files

The C interfaces for this function are specified in the mkl_pblas.h include file.

Description

The p?geadd routines perform sum operation for two distributed general matrices. The operation is defined as sub(C):=beta*sub(C) + alpha*op(sub(A)),

where:

op(x) is one of op(x) = x, or op(x) = x',

alpha and beta are scalars,

sub(C) is an m-by-n distributed matrix, sub(C)=C(ic:ic+m-1, jc:jc+n-1).

sub(A) is a distributed matrix, sub(A)=A(ia:ia+n-1, ja:ja+m-1).

Input Parameters

trans

(global) CHARACTER*1. Specifies the operation:

if trans = 'N' or 'n', then op(sub(A)) := sub(A);

if trans = 'T' or 't', then op(sub(A)) := sub(A)';

if trans = 'C' or 'c', then op(sub(A)) := sub(A)'.

m

(global) INTEGER. Specifies the number of rows of the distributed matrix sub(C) and the number of columns of the submatrix sub(A), m ≥ 0.

n

(global) INTEGER. Specifies the number of columns of the distributed matrix sub(C) and the number of rows of the submatrix sub(A), n ≥ 0.

alpha

(global) REAL for psgeadd

DOUBLE PRECISION for pdgeadd

COMPLEX for pcgeadd

DOUBLE COMPLEX for pzgeadd

Specifies the scalar alpha.

a

(local) REAL for psgeadd

DOUBLE PRECISION for pdgeadd

COMPLEX for pcgeadd

DOUBLE COMPLEX for pzgeadd

Array, DIMENSION (lld_a, LOCq(ja+m-1)). This array contains the local pieces of the distributed matrix sub(A).

ia, ja

(global) INTEGER. The row and column indices in the distributed matrix A indicating the first row and the first column of the submatrix sub(A), respectively.

desca

(global and local) INTEGER array of dimension 8. The array descriptor of the distributed matrix A.

beta

(global) REAL for psgeadd

DOUBLE PRECISION for pdgeadd

COMPLEX for pcgeadd

DOUBLE COMPLEX for pzgeadd

Specifies the scalar beta.

When beta is equal to zero, then sub(C) need not be set on input.

c

(local) REAL for psgeadd

DOUBLE PRECISION for pdgeadd

COMPLEX for pcgeadd

DOUBLE COMPLEX for pzgeadd

Array, DIMENSION (lld_c, LOCq(jc+n-1)).

This array contains the local pieces of the distributed matrix sub(C).

ic, jc

(global) INTEGER. The row and column indices in the distributed matrix C indicating the first row and the first column of the submatrix sub(C), respectively.

descc

(global and local) INTEGER array of dimension 8. The array descriptor of the distributed matrix C.

Output Parameters

c: Overwritten by the updated submatrix.