# VecAXPY#

Computes y = alpha x + y.

## Synopsis#

```
#include "petscvec.h"
PetscErrorCode VecAXPY(Vec y, PetscScalar alpha, Vec x)
```

Logically Collective on Vec

## Input Parameters#

the scalar**alpha -**the vectors**x, y -**

## Output Parameter#

output vector**y -**

## Notes#

x and y MUST be different vectors This routine is optimized for alpha of 0.0, otherwise it calls the BLAS routine

```
VecAXPY(y,alpha,x) y = alpha x + y
```

```
VecAYPX(y,beta,x) y = x + beta y
```

```
VecAXPBY(y,alpha,beta,x) y = alpha x + beta y
```

```
VecWAXPY(w,alpha,x,y) w = alpha x + y
```

```
VecAXPBYPCZ(w,alpha,beta,gamma,x,y) z = alpha x + beta y + gamma z
```

```
VecMAXPY(y,nv,alpha[],x[]) y = sum alpha[i] x[i] + y
```

## See Also#

`VecAYPX()`

, `VecMAXPY()`

, `VecWAXPY()`

, `VecAXPBYPCZ()`

, `VecAXPBY()`

## Level#

intermediate

## Location#

## Examples#

src/vec/vec/tutorials/ex1.c.html

src/vec/vec/tutorials/ex1f90.F90.html

src/vec/vec/tutorials/ex1f.F90.html

src/vec/vec/tutorials/ex20f90.F90.html

src/vec/vec/tutorials/performance.c.html

src/mat/tutorials/ex2.c.html

src/mat/tutorials/ex9.c.html

src/dm/impls/stag/tutorials/ex1.c.html

src/dm/impls/stag/tutorials/ex2.c.html

src/dm/impls/stag/tutorials/ex3.c.html

src/dm/tutorials/ex10.c.html

## Implementations#

VecAXPY_Nest in src/vec/vec/impls/nest/vecnest.c

{
VecAXPY_Seq in src/vec/vec/impls/seq/bvec1.c

{
VecAXPY_SeqKokkos in src/vec/vec/impls/seq/kokkos/veckok.kokkos.cxx

{
VecAXPY_SeqCUDA in src/vec/vec/impls/seq/seqcuda/veccuda2.cu

{
VecAXPY_SeqHIP in src/vec/vec/impls/seq/seqhip/vechip2.hip.c

{
VecAXPY_SeqViennaCL in src/vec/vec/impls/seq/seqviennacl/vecviennacl.cxx

{

Index of all Vec routines

Table of Contents for all manual pages

Index of all manual pages