Johan Hake wrote: > On Saturday 23 January 2010 08:42:14 Garth N. Wells wrote: >> Is it correct that behind the scenes that >> >> U0 = Function(V) >> U = Function(V) >> U0.vector()[:] = U.vector()[:] >> >> involves a GenericVector::get(..) call and a GenericVector::set(..) >> call? If so, it isn't ideal since it introduces unnecessary new/delete >> operations and unnecessary copying of data. > > None of GenericVector::get(..) or GenericVector::set(..) are invoked, see > __getslice__ and __setslice__ in la_post.i. > > U0.vector()[:] > > involves > > GenericVector::operator =(..) > > and > > U.vector()[:] > > involves > > GenericVector::copy() > > However the latter is unnecessary as you instead can do: > > U0.vector()[:] = U.vector() > > invoking the assignment operator of U0's vector with U's vector. >
What happens if I do x = U.vector()[:] ? Is x a numpy array? Garth > Johan > > _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
