petsc-3.14.6 2021-03-30
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VecGetArray

 Returns a pointer to a contiguous array that contains this processor's portion of the vector data. For the standard PETSc vectors, VecGetArray() returns a pointer to the local data array and does not use any copies. If the underlying vector data is not stored in a contiguous array this routine will copy the data to a contiguous array and return a pointer to that. You MUST call VecRestoreArray() when you no longer need access to the array.

Synopsis

#include "petscvec.h"   
PetscErrorCode VecGetArray(Vec x,PetscScalar **a)
Logically Collective on Vec

Input Parameter

x - the vector

Output Parameter

a - location to put pointer to the array

Fortran Note

This routine is used differently from Fortran 77 
   Vec         x

   PetscScalar x_array(1)

   PetscOffset i_x

   PetscErrorCode ierr

      call VecGetArray(x,x_array,i_x,ierr)



  Access first local entry in vector with



     value = x_array(i_x + 1)





     ...... other code



      call VecRestoreArray(x,x_array,i_x,ierr)


For Fortran 90 see VecGetArrayF90()


See the Fortran chapter of the users manual and
petsc/src/snes/tutorials/ex5f.F for details.






See Also

 VecRestoreArray(), VecGetArrayRead(), VecGetArrays(), VecGetArrayF90(), VecGetArrayReadF90(), VecPlaceArray(), VecGetArray2d(),

VecGetArrayPair(), VecRestoreArrayPair(), VecGetArrayWrite(), VecRestoreArrayWrite()

Level
beginner


Location

src/vec/vec/interface/rvector.c

Examples

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

src/vec/vec/tutorials/ex3.c.html

src/vec/vec/tutorials/ex6.c.html

src/vec/vec/tutorials/ex9.c.html

src/vec/vec/tutorials/ex18.c.html

src/vec/vec/tutorials/ex19.c.html

src/vec/vec/tutorials/ex21.c.html

src/vec/vec/tutorials/ex4f.F.html

src/vec/is/sf/tutorials/ex2.c.html

src/dm/tutorials/ex5.c.html

src/dm/tutorials/ex6.c.html


Implementations
VecGetArray_Nest in src/vec/vec/impls/nest/vecnest.c

VecGetArray_Node in src/vec/vec/impls/node/vecnode.c


Index of all Vec routines

Table of Contents for all manual pages

Index of all manual pages