Garth N. Wells wrote: > > > Johan Hake wrote: >> On Thursday 02 July 2009 15:17:08 Garth N. Wells wrote: >>> Johan Hake wrote: >>>> On Thursday 02 July 2009 22:48:18 Marie Rognes wrote: >>>>> Johan Hake wrote: >>>>>> On Thursday 02 July 2009 13:24:28 Garth N. Wells wrote: >>>>>>> Johan Hake wrote: >>>>>>>> On Thursday 02 July 2009 13:07:47 Garth N. Wells wrote: >>>>>>>>> Marie Rognes wrote: >>>>>>>>>> Garth N. Wells wrote: >>>>>>>>>>> Marie Rognes wrote: >>>>>>>>>>>> The following code gives r = 0.0. It is not supposed to be. >>>>>>>>>>>> >>>>>>>>>>>> The problem seems to be that f's vector is still all zeros >>>>>>>>>>>> at the >>>>>>>>>>>> call to interpolate. Could this be easily fixed? >>>>>>>>>>> This example should have led to an error message since f is >>>>>>>>>>> not a >>>>>>>>>>> discrete function. I'll take a look. >>>>>>>>>> Ok, thanks! >>>>>>>>>> >>>>>>>>>> However, >>>>>>>>>> >>>>>>>>>> (a) Why is f not a discrete function? (It is defined on a finite >>>>>>>>>> element space?) >>>>>>>>> On second thought, it may be a discrete function. I think that >>>>>>>>> this >>>>>>>>> is defined in the Python interface and not the C++ interface, so >>>>>>>>> I'll take a look. >>>>>>>> A user defined function is not a discrete function untill you >>>>>>>> either >>>>>>>> call interpolate() or vector, also in python. The problem with the >>>>>>>> later is that you then create a vector which is initialized to 0. >>>>>>>> >>>>>>>> I think this has been discussed before, but should we populate the >>>>>>>> vector using f.interpolate() when vector is called on a >>>>>>>> userdefined >>>>>>>> function? >>>>>>> Or perhaps Function::vector() should throw an error if the >>>>>>> vector has >>>>>>> not already been allocated. >>>>>> I vote for this. >>>>>> >>>>>> The error message can include information about the user might >>>>>> want to >>>>>> call interpolate? >>>>> What is wrong with actually populating the vector with the values one >>>>> expects it to have? >>>>> (When would one not want this?) >>>> Nothing is wrong with that. It just changes the state of the >>>> userdefined >>>> function. The question is should this change be the implicit result >>>> of a >>>> call to Function::vector() or should it be a result of an explicit >>>> action: a call to Function::interpolate(). >>>> >>>>> Also note that it is not intuitive to me that one must call >>>>> f.interpolate() before >>>>> >>>>> Pi_f = interpolate(f, Q_h) >>> I thought that I removed the above function from the C++ interface and >>> added >>> >>> Pi_f = interpolate(f) >> > > Oops, I meant that I removed > > Pi_f.interpolate(f, Q_h) > > and added > > Pi_f.interpolate(f) > > I think that we should remove interpolate.py. It's now a wrapper for > only two lines of code. >
If so, if I want to interpolate f (defined on V_h) onto the space Q_h, I should do ...? -- Marie _______________________________________________ DOLFIN-dev mailing list DOLFIN-dev@fenics.org http://www.fenics.org/mailman/listinfo/dolfin-dev
