Barry, Thanks for the prompt change ! I do not work on the development version but I can update these matrix routines alone.
> ?Note it can still glitch if the restricted size is exactly the original > size. :-( Why would it glitch if the restricted size is the same as the original size though ? I dont see a case where your check (M==Ny) would fail. Can you please elaborate more on this ? Vijay On Wed, Dec 15, 2010 at 8:04 PM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > ?I have pushed this change to petsc-dev and it is ready for use. > > ? Barry > > ?Note it can still glitch if the restricted size is exactly the original > size. :-( > > > On Dec 15, 2010, at 7:53 PM, Barry Smith wrote: > >> >> ?Vijay, >> >> ? ?The use of M>N in MatRestrict and MatInterpolate was always a bit cheesy >> since it has this broken case that you reported. I will change it to do as >> you suggest and use the size of the vectors in determining which way to >> apply. But note I will do this in petsc-dev >> http://www.mcs.anl.gov/petsc/petsc-as/developers/index.html not petsc-3.1 so >> you'll need to switch if you are not using petsc-dev. >> >> ? I'll try to get it down in the next few hours but it may take a little >> longer. >> >> >> ? Barry >> >> On Dec 15, 2010, at 6:06 PM, Vijay S. Mahadevan wrote: >> >>> Hi, >>> >>> I have an implementation issue with the MatRestrict/Interpolate >>> functions. The problem is that one of my coarser levels (with PCMG) >>> has higher dofs than the finest level. This does not always happen and >>> requires a weird fine mesh system (in a sense) that uses multi-grid, >>> but the idea is that the finest level problem has a high order (HO) >>> discretization while the lower level mesh has a linear tesselation of >>> the finest HO level (which I can optimize) and then adaptively >>> coarsened levels beyond that. Since the number of columns in this case >>> is larger than the number of rows, MatRestrict invariably calls >>> MatMultTranspose to multiply instead of MatMult and vice-versa while >>> calling ?MatInterpolate. These result in assertion errors while >>> comparing the length of Mat and Vec. The chosen method is based on >>> whether (M>N) which seems to act against what I am doing here... >>> >>> I can always implement a shell matrix to replicate >>> Restrict/Interpolate actions but my question is whether if such >>> discretization will yield a consistent convergence in MG algorithm ? >>> Is there a strong reason for checking if (M>N) rather than just doing >>> (mat->rmap->N==y->map->N && mat->cmap->N==x->map->N) ? I would >>> appreciate any detailed answer that you can provide for this and any >>> suggestions to use the existing methods (without implementing the >>> shell restriction) is very welcome. >>> >>> Thanks, >>> vijay >> > >
