You can take the derivatives of an UFL expression, but not an dolfin.Expression (which represents compiled code).
Try this for example: from dolfin import * mesh = UnitSquare(20, 20) cell = mesh.ufl_cell() x = cell.x f = sin(2*pi*(x[0]**2 + x[1]**2)) plot(project(grad(f), mesh=mesh)) interactive() Martin On 31 May 2011 18:41, Praveen C <question159...@answers.launchpad.net> wrote: > Question #159771 on DOLFIN changed: > https://answers.launchpad.net/dolfin/+question/159771 > > Praveen C gave more information on the question: > I know I can interpolate and Expression and then take grad. But I am > looking to see if there is some automatic differentiation of an > Expression available in dolfin. > > -- > 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 > 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
