Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 6/24/2024
Public

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Document Table of Contents

?ger

Performs a rank-1 update of a general matrix.

Syntax

call sger(m, n, alpha, x, incx, y, incy, a, lda)

call dger(m, n, alpha, x, incx, y, incy, a, lda)

call ger(a, x, y [,alpha])

Include Files

  • mkl.fi, blas.f90

Description

The ?ger routines perform a matrix-vector operation defined as

					A := alpha*x*y'+ A,

where:

alpha is a scalar,

x is an m-element vector,

y is an n-element vector,

A is an m-by-n general matrix.

Input Parameters

m

INTEGER. Specifies the number of rows of the matrix A.

The value of m must be at least zero.

n

INTEGER. Specifies the number of columns of the matrix A.

The value of n must be at least zero.

alpha

REAL for sger

DOUBLE PRECISION for dger

Specifies the scalar alpha.

x

REAL for sger

DOUBLE PRECISION for dger

Array, size at least (1 + (m - 1)*abs(incx)). Before entry, the incremented array x must contain the m-element vector x.

incx

INTEGER. Specifies the increment for the elements of x.

The value of incx must not be zero.

y

REAL for sger

DOUBLE PRECISION for dger

Array, size at least (1 + (n - 1)*abs(incy)). Before entry, the incremented array y must contain the n-element vector y.

incy

INTEGER. Specifies the increment for the elements of y.

The value of incy must not be zero.

a

REAL for sger

DOUBLE PRECISION for dger

Array, size (lda, n).

Before entry, the leading m-by-n part of the array a must contain the matrix of coefficients.

lda

INTEGER. Specifies the leading dimension of a as declared in the calling (sub)program.

The value of lda must be at least max(1, m).

Output Parameters

a

Overwritten by the updated matrix.

BLAS 95 Interface Notes

Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see BLAS 95 Interface Conventions.

Specific details for the routine ger interface are the following:

a

Holds the matrix A of size (m,n).

x

Holds the vector with the number of elements m.

y

Holds the vector with the number of elements n.

alpha

The default value is 1.