open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,

I have recompiled Paraview (3.14.0) on Linux with the Serafin plugin. It works well for 2D and 3D outputs. Now I want to compute the difference (let's call it MYDIFF) between the same field (let's call it MYVARIABLE) of two output files. Once loaded I use the following Programmable Filter (from the Filter/Data Analysis Menu) :
output.PointData.append(inputs[1].PointData-inputs[0].PointData,'MYDIFF')

I get the following error message :

Traceback (most recent call last):
File "<string>", line 28, in <module>
File "<string>", line 2, in RequestData
TypeError: unsupported operand type(s) for -: 'NoneType' and 'NoneType'

This filter use to work when I was using vtk files, but I have an old version of this and I though Serafin plugin was quite handy instead of converting everything ...

Does that ring a bell to anyone ? Any way around this ?

Thanks

Sophie