# CXXBLAS Level 1: axpy

axpy (defined in namespace cxxblas) computes $$y \leftarrow y +\alpha x$$ where $$x, y$$ are vectors and $$\alpha$$ is a constant scalar.

## Generic Implementation

 n (input) Specifies the number of elements in vector $$x$$ and $$y$$. alpha (input) Scaling factor for the values in $$x$$. x (input) Pointer to the first element of vector $$x$$. incX (input) Specifies the increment for indexing vector $$x$$. y (input/output) Pointer to the first element of vector $$y$$. incY (input) Specifies the increment for indexing vector $$y$$.

## CBLAS Implementation

If a CBLAS implementations like ATLAS, GotoBLAS, ... is available then the following optimized variants are provided.