VecAXPY#

Computes y = alpha x + y.

Synopsis#

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

Logically Collective

Input Parameters#

  • alpha - the scalar

  • x, y - the vectors

Output Parameter#

  • y - output vector

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#

src/vec/vec/interface/rvector.c

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


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