On Wed, Jan 25, 2017 at 11:12 PM, Adrian Croucher <[email protected] > wrote:
> hi Matt, > > A couple of years ago we discussed adding support for 6-node wedge cells > in DMPlex- the hurdle being that at present DMPlex doesn't support cells > with faces of different shapes (see below)- and you said it could be done, > if and when I needed it. > > People are starting to want to use my code on real models now, many of > which have 6-node wedge cells. So it would be very handy to have support > for those in DMPlex fairly soon if possible. > > Any chance you would be able to take a look at it? In principle I would be > happy to help if I can. I have started looking at plexinterpolate.c to try > and see how it works, but at this stage I'm not at all confident that I > understand the subtleties. > Okay. First I need to understand exactly what shape we want to handle. Can you draw it or explain precisely? Second, we need to prescribe a total order on the vertices for a wedge, and then a set of faces as ordered arrays of vertices. That information goes here: https://bitbucket.org/petsc/petsc/src/e8e596daf24561903cea0839b7b68a432a6283e4/src/dm/impls/plex/plexinterpolate.c?at=master&fileviewer=file-view-default#plexinterpolate.c-37 I think that might be all we have to do, but until you try something, secret assumptions lurking in the code are not obvious. Thanks, Matt > Cheers, Adrian > > > On 16/04/14 08:42, Matthew Knepley wrote: > > > Yeah, I was afraid that might be the workaround ;-) It seems to me that > for a large unstructured mesh, creating the whole DAG would basically > amount to duplicating what the very handy DMPlexInterpolate() function does. > > > The problem here is that if I allow faces of different shapes, I have to > keep track of the shape of each > face when I make it. This is possible, and I have added it to the TODO > list, but I think it will be a while > before I get to it. If you want to try doing it, I would help. > > > I'd have to get more familiar with how it works first, and it probably > isn't top of my priority list either at present- I can continue getting my > code together without support for wedge cells at the moment. But at some > point I will need it. > > > Okay, when you need it, we will make it work. > > > -- > > Dr Adrian Croucher > Senior Research Fellow > Department of Engineering Science > University of Auckland, New Zealand > email: [email protected] > tel: +64 (0)9 923 4611 <+64%209-923%204611> > > -- 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
