?ger

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 4/28/2026

Version

Public

?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, mkl_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

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

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. 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

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) . 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.

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.

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

?ger

Syntax

Include Files

Description

Input Parameters

Output Parameters

BLAS 95 Interface Notes