On Thu, Sep 24, 2009 at 04:13:25PM -0500, Robert Kirby wrote: > Anders, two comments: > 1.) You should use de Casteljau's algorithm for the Bernstein > polynomials.
I'm not aware of that, but I'll make a note of it for when the time comes to reimplement it in C++ (for Andre ;-). > 2.) Using the recurrence relations in new version of FIAT will avoid > the singular mapping and should allow evaluation outside the reference > simplex. Nice! > But we need to make time to smooth this version out and > hook it up to ffc. Yes, I won't be able to do it just now. Maybe after the deadline for the FEniCS book chapters. -- Anders > Rob > > On Wed, Sep 23, 2009 at 6:00 PM, Anders Logg <l...@simula.no> wrote: > > I just went through implementing Bernstein polynomials in Python > because Marie and I needed them for our experiments with adaptivity > and the FIAT basis functions could not be evaluated outside the > triangles (the mapping being singular along y = 1). > > I've attached the code for the Bernstein polynomials. We will need to > implement this in C++ at some point when things are working. > > > > On Wed, Sep 23, 2009 at 05:53:30PM -0500, Robert Kirby wrote: > > It probably should be added in dolfin/ufc. Sometimes we want to play > around > > with things that aren't supported by ffc yet. Having a full-featured > c++ > > library (and python bindings) would help. An example would be Berstein > > polynomials, which use a different evaluation method than in ffc/fiat. > Another > > example is the transformation business I'm working that needs cell > jacobians > > and other geometric information. I'd like to look at hand-done > implementations > > using the dolfin library (preferably PyDolfin) to make sure stuff works > before > > going through the labor of teaching ffc how to do it. > > > > Rob > > > > On Wed, Sep 23, 2009 at 5:45 PM, Garth N. Wells <gn...@cam.ac.uk> wrote: > > > > > > > > Robert Kirby wrote: > > > > Is there a method for getting the Jacobian of a mapping to a > reference > > cell in dolfin, or is this always generated by ffc? > > > > > > > > It's generated by FFC. Could be a suggestion for an addition to UFC. > > > > Garth > > > > > > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > DOLFIN-dev mailing list > > DOLFIN-dev@fenics.org > > http://www.fenics.org/mailman/listinfo/dolfin-dev > > > > > > > > > > > > > _______________________________________________ > > DOLFIN-dev mailing list > > DOLFIN-dev@fenics.org > > http://www.fenics.org/mailman/listinfo/dolfin-dev > > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (GNU/Linux) > > iEYEARECAAYFAkq6qI8ACgkQTuwUCDsYZdGEcACcD3FgXBQdSkw2n9/N0G2sVnxf > aMEAnRfNwekxL8KIxr3cihiwGCi749LC > =jVWS > -----END PGP SIGNATURE----- > > _______________________________________________ > DOLFIN-dev mailing list > DOLFIN-dev@fenics.org > http://www.fenics.org/mailman/listinfo/dolfin-dev > > > > _______________________________________________ > DOLFIN-dev mailing list > DOLFIN-dev@fenics.org > http://www.fenics.org/mailman/listinfo/dolfin-dev
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