petsc-3.14.6 2021-03-30

DMDAGetRay

Returns a vector on process zero that contains a row or column of the values in a DMDA vector

#include "petscdmda.h"   
PetscErrorCode  DMDAGetRay(DM da,DMDirection dir,PetscInt gp,Vec *newvec,VecScatter *scatter)

Collective on DMDA

	da	- the distributed array
	vec	- the vector
	dir	- Cartesian direction, either DM_X, DM_Y, or DM_Z
	gp	- global grid point number in this direction

	newvec	- the new vector that can hold the values (size zero on all processes except process 0)
	scatter	- the VecScatter that will map from the original vector to the slice

All processors that share the DMDA must call this with the same gp value

advanced