<div dir="ltr"><div>1) Is there somewhere on the doc site with a single list of all examples and what they do? As a new user I hugely appreciate all the great examples and documentation, but it's a little unwieldy to try and find relevant examples by navigating the function documents.</div>
<div><br></div>2) I'm a little unclear as to the best-practice way to handle solution/grid related data that isn't actual solution DOFS or mesh points, and doesn't require global communication.<br><br>Say I want to work on an (ni X nj ) cell-centered finite volume layout with one DOF per cell. I start with<div>
<br></div><div><div>DMDACreate2d(PETSC_COMM_WORLD,</div><div><span class="" style="white-space:pre"> </span> DMDA_BOUNDARY_PERIODIC, DMDA_BOUNDARY_NONE, /* periodic in i, no conn in j */</div><div><span class="" style="white-space:pre"> </span> DMDA_STENCIL_BOX, /* 5-point stencil */</div>
<div><span class="" style="white-space:pre"> </span> ni,nj, /* number of cells */</div><div><span class="" style="white-space:pre"> </span> PETSC_DECIDE,PETSC_DECIDE, /* let petsc determine number of procs */</div>
<div><span class="" style="white-space:pre"> </span> 1, /* one degree of freedom per cell */</div><div><span class="" style="white-space:pre"> </span> 1, /* stencil width */</div><div><span class="" style="white-space:pre"> </span> NULL,NULL,&da);</div>
</div><div><br></div><div>Now I can construct the solution vector like so:</div><div><br></div><div>struct Field { PetscScalar u; };</div><div>Field **soln;</div><div>Vec global_vec;</div><div>DMDACreateGlobalVector(da,&global_vec);</div>
<div>DMDAVecGetArray(da,global_vec,&soln); // converts global vector into Field** </div><div><br></div><div>and access the local elements through soln[j][i]. But say I want to store some grid information locally, say the FaceNormal for a cell face:</div>
<div>struct FaceNormal{ PetscScalar nx,ny; };</div><div>FaceNormal **IFace;</div><div><br></div><div>Now it seems that the CreateGlobalVector/CreateLocalVector are just going to allocate for 1 DOF because of how the DMDA was defined, so there wouldn't be sufficient storage for the 2 variables in FaceNormal. What's an appropriate way to do this? Clearly I could just malloc that myself, but it'd be nice to keep the same indexing as the petsc vectors.</div>
<div><br></div><div>Thanks in advance,</div></div>