On Wed, Oct 11, 2017 at 10:58 AM, Matthew Knepley <[email protected]> wrote:
> On Wed, Oct 11, 2017 at 4:54 AM, Patrick Sanan <[email protected]> > wrote: > >> Another terminology question to help with the docs. >> >> What's the origin of the term "chart" in DMPlex? I'm only previously >> familiar with the term in the context of manifolds (where chart = >> homeomorphism from an open set in the manifold to an open set in R^n). >> > > That is what it is supposed to be. A chart is coordinates on a patch of > the manifold. We intend the same thing here in that you can > locally refer to points with a given name, but they may have a different > name on another chart (process). The names are matched up using the PetscSF. > So do you mean that you think of the DMPlex (thought of just as a set of points) as some kind of a "manifold over the integers" and consider an "atlas" with one patch per proc, with the SF defining the "transition maps"? > >> In terms of the use in DMPlex, is there anything wrong with thinking of >> "chart" as a shorter way to say "interval of integers, closed on the left >> and open on the right, e.g. [pStart,pEnd)"? >> > > No, since we depend on continuity of point names almost everywhere. > > Matt > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > -- Norbert Wiener > > https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/> >
