Lisandro wrote this. Not sure if it is checked in. Sent from my iPhone
On Jun 8, 2012, at 5:18 PM, Richard Katz <Richard.Katz at earth.ox.ac.uk> wrote: > Hi all, > > Writing to ask that you again consider this feature request. > > Thanks, > Rich > > > On Jan 8, 2012 2:43 PM, "Richard Katz" <richard.katz at earth.ox.ac.uk> wrote: >> Dear all, >> >> I wonder if I can interest you in a new DMDA boundary type... that I'd >> probably need for you to implement... and it might be slightly painful. >> >> The idea is a periodic boundary with a 180 degree topological "twist." (i.e. >> Mobius strip in 2D). I'll call it DMDA_BOUNDARY_PERIODIC_TWIST here for >> sake of argument. >> >> If I have a 1D DMDA, this is meaningless. >> >> If I have a 2D array with DMDA_BOUNDARY_PERIODIC_TWIST as my periodic type >> in the y-direction, then the row of ghost points at the y-limits of the grid >> would be as for DMDA_BOUNDARY_PERIODIC, but with the order of values in the >> x-direction reversed. >> >> In 3D this would be more complicated, because a PERIODIC_TWIST boundary >> condition in one direction could involve twists in either/both of the other >> directions. >> >> I'd be thrilled with just the 2D version. What do you think? >> >> Cheers, >> Rich >> >> >> ps - my motivation: consider a 2D fluid undergoing simple shear as a >> background strain-rate field. I am solving for a perturbation to this >> background field. I would like the perturbation to be periodic in all >> directions. Because the perturbation field is advected by the background >> field, this can only work with Mobius-strip periodicity in the direction >> normal to the shear direction. > > > > On 23 May 2012, at 15:27, Jed Brown wrote: > >> We're basically in code freeze for the 3.3 release now, but I will get back >> to this. Sorry for dragging on. >> >
