I have studied FreeFEM++ and its parallelization with lectures in Youtube made by Pierre Jolivet and TuxRiders. During self-studies, I got a simple question but making me slightly confused of.
The thing is,
As far as I know,
buildDmesh is a function of decomposing the whole domain to subdomains based on the number of allocated MPI processors. One the other hand,
createMat is to distribute a PETSc matrix from “Mat” in PETSc library for parallel computation.
So, I could see that in Pierre’s lecture, he used buildDmesh and createMesh together while TuxRiders’s recent video ([FreeFEM 11] Domain decomposition and high-performance finite element simulations - YouTube) used createMesh without buildDMesh. This makes me slightly confused.
Thus, my question is, is it fine to use createMesh only without buildDmesh?