Developer Reference for Intel® oneAPI Math Kernel Library for C

ID 766684
Date 11/07/2023
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

cblas_?ger

Performs a rank-1 update of a general matrix.

Syntax

void cblas_sger (const CBLAS_LAYOUT Layout, const MKL_INT m, const MKL_INT n, const float alpha, const float *x, const MKL_INT incx, const float *y, const MKL_INT incy, float *a, const MKL_INT lda);

void cblas_dger (const CBLAS_LAYOUT Layout, const MKL_INT m, const MKL_INT n, const double alpha, const double *x, const MKL_INT incx, const double *y, const MKL_INT incy, double *a, const MKL_INT lda);

Include Files

  • mkl.h

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

Layout

Specifies whether two-dimensional array storage is row-major (CblasRowMajor) or column-major (CblasColMajor).

m

Specifies the number of rows of the matrix A.

The value of m must be at least zero.

n

Specifies the number of columns of the matrix A.

The value of n must be at least zero.

alpha

Specifies the scalar alpha.

x

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

incx

Specifies the increment for the elements of x.

The value of incx must not be zero.

y

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

incy

Specifies the increment for the elements of y.

The value of incy must not be zero.

a

Array, size lda*k.

For Layout = CblasColMajor, k is n. Before entry, the leading m-by-n part of the array a must contain the matrix A.

For Layout = CblasRowMajor, k is m. Before entry, the leading n-by-m part of the array a must contain the matrix A.

lda

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

For Layout = CblasColMajor, the value of lda must be at least max(1, m).

For Layout = CblasRowMajor, the value of lda must be at least max(1, n).

Output Parameters

a

Overwritten by the updated matrix.