On Saturday 27 February 2010 12:49:23 Garth N. Wells wrote: > On Sat, 2010-02-27 at 19:58 +0100, Anders Logg wrote: > > On Sat, Feb 27, 2010 at 06:32:12PM +0000, Garth N. Wells wrote: > > > How do I pass the pointer to the first element of an array from the > > > Python interface to a wrapped C++ function? I would like to tabulate > > > the dofs of a cell, so I tried > > > > > > local_facet = cell.index(facet) > > > dofs = numpy.array(9, dtype=numpy.uint32) > > > dof_map.tabulate_facet_dofs(dofs, local_facet) > > > > > > but I get a bunch of memory errors. I don't know to correctly allocate > > > 'dofs' such that I can pass it to tabulate_facet_dofs. > > > > Try this: > > > > cell_dofs = numpy.zeros(n, dtype='I') > > Thanks. Did the trick.
An exception should have been raised here asking you to pass an array with dtype='I'. Btw, I have never figured out the difference between the different uintXX in NumPy, versus the string descriptors. Johan > Garth > > > It has worked for me before. Also note that there are dolfin::Cell > > functions for some (but not all) of the functions in DofMap which > > allows access from Python without needing to create a ufc::cell. > > > > -- > > Anders > > _______________________________________________ > Mailing list: https://launchpad.net/~dolfin > Post to : [email protected] > Unsubscribe : https://launchpad.net/~dolfin > More help : https://help.launchpad.net/ListHelp > _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
