Thanks, Likun
On Wed, August 31, 2011 5:11 pm, Ethan Coon wrote: > On Wed, 2011-08-31 at 16:23 -0400, Likun Tan wrote: > >> Hello, >> >> >> I have a quick question about DA. When use DAVecGetArray() to set >> values to the array and run the program with mpiexec, does >> DAVecGetArray() >> compute in parallel? >> > > DAVecGetArray() only gives you access to the local portion (plus any > ghost nodes) of the global vec. The portion of the data you get is indexed > by global numbering, so the indices into the pointer should range from > > xs --> xs+m > > where these values are given by > > DAGetGhostCorners() or DAGetCorners() > > > http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manual > pages/DA/DAGetGhostCorners.html#DAGetGhostCorners > > So yes, you should only do the local portion of the calculation to set > set the values. > > Ethan > > >> Thanks in advance, >> Likun >> >> >> >> >> > > -- > ------------------------------------ > Ethan Coon > Post-Doctoral Researcher > Applied Mathematics - T-5 > Los Alamos National Laboratory > 505-665-8289 > > > http://www.ldeo.columbia.edu/~ecoon/ > ------------------------------------ > > > >
