?gerc

Developer Reference for Intel® oneAPI Math Kernel Library for C

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ID 766684

Date 4/28/2026

Version

Public

?gerc

Performs a rank-1 update (conjugated) of a general matrix.

Syntax

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

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

Include Files

mkl.h

Description

The ?gerc routines perform a matrix-vector operation defined as A := alpha * x *conjg( 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 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: COMPLEX for cgerc DOUBLE COMPLEX for zgerc Specifies the scalar alpha .
x: COMPLEX for cgerc DOUBLE COMPLEX for zgerc 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: COMPLEX for cgerc DOUBLE COMPLEX for zgerc 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: COMPLEX for cgerc DOUBLE COMPLEX for zgerc 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

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

There exist FORTRAN 77 and FORTRAN 95 interfaces for this routine. See the Intel® oneMKL Fortran Developer Reference for details.

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Developer Reference for Intel® oneAPI Math Kernel Library for C

?gerc

Syntax

Include Files

Description

Input Parameters

Output Parameters

BLAS 95 Interface Notes