The permutation symbol should be added to UFL. Garth
On 13/04/11 19:20, Martin Sandve Alnæs wrote: > Python does not know anything about implicit index summation, so in your > code e() is only called once, and reaches the else condition and thus > returns 0.0. > > Similar to as_vector, you can use the as_tensor function, since you need > three dimensions. > > Martin > > On 13 April 2011 19:04, B. Emek Abali > <question152...@answers.launchpad.net > <mailto:question152...@answers.launchpad.net>> wrote: > > New question #152702 on DOLFIN: > https://answers.launchpad.net/dolfin/+question/152702 > > May be a non-needed trial for some, but I try to define an > expression (permutation symbol) > > def e(i,j,k): > if (i,j,k) == (1.0,2.0,3.0): return 1.0 > elif (i,j,k) == (2.0,3.0,1.0): return 1.0 > elif (i,j,k) == (3.0,1.0,2.0): return 1.0 > elif (i,j,k) == (3.0,2.0,1.0): return -1.0 > elif (i,j,k) == (2.0,1.0,3.0): return -1.0 > elif (i,j,k) == (1.0,3.0,2.0): return -1.0 > else: return 0.0 > > and use (with summation over indices, it is a curl operator > contracted with w) in the form like > > f=v[j]*w[i]*e(i,j,l)*v[l]*dx > > which raises: > ufl.log.UFLException: Trying to integrate expression of rank 0 with > free indices > > Do I have to use as_vector(...) type definition to sum with indices > or is there a nice possibility to let it sum over the arguments of > e(...) expression? > > -- > You received this question notification because you are a member of > DOLFIN Team, which is an answer contact for DOLFIN. > > _______________________________________________ > Mailing list: https://launchpad.net/~dolfin > Post to : dolfin@lists.launchpad.net > <mailto:dolfin@lists.launchpad.net> > Unsubscribe : https://launchpad.net/~dolfin > More help : https://help.launchpad.net/ListHelp > > > > > _______________________________________________ > Mailing list: https://launchpad.net/~dolfin > Post to : dolfin@lists.launchpad.net > Unsubscribe : https://launchpad.net/~dolfin > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
