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. >
