On Wednesday December 21 2011 19:33:23 Johan Hake wrote: > On Wednesday December 21 2011 18:00:23 Garth N. Wells wrote: > > What happens behind the scenes when for > > > > x = Vector(100) > > > > ones does > > > > x[:] > > > > ? > > That depends if x[:] is on the lhs or on the rhs. If it is on the rhs a > copy will be returned. This is a slice convention in Python. > > l0 = range(5) > l1 = l[:] > l1[0] = 1
For clarity: l0 = range(5) l1 = l0[:] l1[0] = 2 :) Johan > The last statement will change l1 but not l0. I would expect the same for > dolfin vectors. > > If it is on lhs and the rhs is either a GeneriVector or a scalar, > x._assign(rhs) will be envoked. > > The relevant methods in la_post.i are: > > def __getslice__(...): > def __setslize__(...): > > Johan > > > I've added GenericVector operator+= and -= for doubles, and would like > > to be sure that this can be used from Python without unnecessary > > copies being made. > > > > Garth > > > > _______________________________________________ > > 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 _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
