DMCreateMatrix() ?
> On Jul 28, 2015, at 9:02 PM, Gideon Simpson <[email protected]> wrote: > > I’m working with a DMComposite where I have a DMRedundant with 2 parameters, > and then a standard DMDACreate with some number of entires that I would like > to have distributed. For concreteness, suppose it is > > DMCompositeCreate(PETSC_COMM_WORLD, &packer); > DMRedundantCreate(PETSC_COMM_WORLD, 0, 2, &p_dm); > DMCompositeAddDM(packer,p_dm); > DMDACreate1d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE, nx, 1, 1, NULL,&u_dm); > DMCompositeAddDM(packer,u_dm); > DMCreateGlobalVector(packer,&U); > > Now, I would like to construct a matrix for this problem that can be used for > computing Jacobians in a nonlinear solve. Is there a way to get the matrix > size to layout in a “useful” way, in the sense that the first process, which > owns the two degrees of freedom of p_dm and the first N0 number of the rows > of u_dm, controls the corresponding N0+2 rows of the matrix, and analgously > for the second process has the next N1 rows of the u_dm vector, and has the > next N1 rows of the matrix? > > -gideon >
