Function

# cblas_cgemv

Multiplies a matrix by a vector (single-precision complex).

## Parameters

Order

Specifies row-major (C) or column-major (Fortran) data ordering.

TransA

Specifies whether to transpose matrix A.

M

Number of rows in matrix A.

N

Number of columns in matrix A.

alpha

Scaling factor for the product of matrix A and vector X.

A

Matrix A.

lda

The size of the first dimention of matrix A; if you are passing a matrix A[m][n], the value should be m.

X

Vector X.

incX

Stride within X. For example, if incX is 7, every 7th element is used.

beta

Scaling factor for vector Y.

Y

Vector Y

incY

Stride within Y. For example, if incY is 7, every 7th element is used.

## Discussion

This function multiplies A * X (after transposing A, if needed) and multiplies the resulting matrix by alpha. It then multiplies vector Y by beta. It stores the sum of these two products in vector Y.

Thus, it calculates either

Y←αAX + βY

with optional use of the transposed form of A.

### Single-Precision Complex Matrix Functions

cblas_caxpy

Computes a constant times a vector plus a vector (single-precision complex).

cblas_ccopy

Copies a vector to another vector (single-precision complex).

cblas_cgbmv

Scales a general band matrix, then multiplies by a vector, then adds a vector (single-precision complex).

cblas_cgemm

Multiplies two matrices (single-precision complex).

cblas_cgerc

Multiplies vector X by the conjugate transpose of vector Y, then adds matrix A (single-precision complex).

cblas_cgeru

Multiplies vector X by the transpose of vector Y, then adds matrix A (single-precision complex).

cblas_chbmv

Scales a Hermitian band matrix, then multiplies by a vector, then adds a vector (single-precision complex).

cblas_chemm

Multiplies two Hermitian matrices (single-precision complex), then adds a third (with scaling).

cblas_chemv

Scales and multiplies a Hermitian matrix by a vector, then adds a second (scaled) vector.

cblas_cher

Hermitian rank 1 update: adds the product of a scaling factor, vector X, and the conjugate transpose of X to matrix A.

cblas_cher2

Hermitian rank 2 update: adds the product of a scaling factor, vector X, and the conjugate transpose of vector Y to the product of the conjugate of the scaling factor, vector Y, and the conjugate transpose of vector X, and adds the result to matrix A.

cblas_cher2k

Performs a rank-2k update of a complex Hermitian matrix (single-precision complex).

cblas_cherk

Rank-k update—multiplies a Hermitian matrix by its transpose and adds a second matrix (single precision).

cblas_chpmv

Scales a packed hermitian matrix, multiplies it by a vector, and adds a scaled vector.

cblas_chpr

Scales and multiplies a vector times its conjugate transpose, then adds a matrix.

cblas_chpr2

Multiplies a vector times the conjugate transpose of a second vector and vice-versa, sums the results, and adds a matrix.

cblas_crotg

Constructs a complex Givens rotation.

cblas_cscal

Multiplies each element of a vector by a constant (single-precision complex).

cblas_csrot

Applies a Givens rotation matrix to a pair of complex vectors.

cblas_csscal

Multiplies each element of a vector by a constant (single-precision complex).

cblas_cswap

Exchanges the elements of two vectors (single-precision complex).

cblas_csymm

Multiplies a matrix by a symmetric matrix (single-precision complex).

cblas_csyr2k

Performs a rank-2k update of a symmetric matrix (single-precision complex).

cblas_csyrk

Rank-k update—multiplies a symmetric matrix by its transpose and adds a second matrix (single-precision complex).

cblas_ctbmv

Scales a triangular band matrix, then multiplies by a vector (single-precision compex).

cblas_ctbsv

Solves a triangular banded system of equations.

cblas_ctpmv

Multiplies a triangular matrix by a vector, then adds a vector (single-precision complex).

cblas_ctpsv

Solves a packed triangular system of equations.

cblas_ctrmm

Scales a triangular matrix and multiplies it by a matrix.

cblas_ctrmv

Multiplies a triangular matrix by a vector.

cblas_ctrsm

Solves a triangular system of equations with multiple values for the right side.

cblas_ctrsv

Solves a triangular system of equations with a single value for the right side.

cblas_scasum

Computes the sum of the absolute values of real and imaginary parts of elements in a vector (single-precision complex).

cblas_scnrm2

Computes the unitary norm of a vector (single-precision complex).