petsc3.13.6 20200929
DMGlobalToLocalSolve
Solve for the global vector that is mapped to a given local vector by DMGlobalToLocalBegin()/DMGlobalToLocalEnd() with mode = INSERT_VALUES. It is assumed that the sum of all the local vector sizes is greater than or equal to the global vector size, so the solution is a leastsquares solution. It is also assumed that DMLocalToGlobalBegin()/DMLocalToGlobalEnd() with mode = ADD_VALUES is the adjoint of the globaltolocal map, so that the leastsquares solution may be found by the normal equations.
Synopsis
#include "petscdm.h"
#include "petscdmplex.h"
#include "petscksp.h"
PetscErrorCode DMGlobalToLocalSolve(DM dm, Vec x, Vec y)
collective
Input Parameters
 dm   The DM object

 x   The local vector

 y   The global vector: the input value of globalVec is used as an initial guess

Output Parameters
y The leastsquares solution
Note: If the DM is of type DMPLEX, then y is the solution of L' * D * L * y = L' * D * x, where D is a diagonal mask that is 1 for every point in
the union of the closures of the local cells and 0 otherwise. This difference is only relevant if there are anchor points that are not in the
closure of any local cell (see DMPlexGetAnchors()/DMPlexSetAnchors()).
See Also
DMGlobalToLocalBegin(), DMGlobalToLocalEnd(), DMLocalToGlobalBegin(), DMLocalToGlobalEnd(), DMPlexGetAnchors(), DMPlexSetAnchors()
Level
advanced
Location
src/ksp/ksp/utils/dmproject.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages