Hi! Thank you very much for the suggestion, but in that case I seem to end up with a function that is constant within each square in the mesh.
A general Q_1,1 function can have different values in each of the four corners of each square, and in the interior it is a first order polynomial w.r.t. each of the variables x and y. Does Paraview support the display of such a function which is not necessarily constant within each square? Best regards, Torquil Sørensen On 23/09/15 10:15, Kaushik Kulkarni wrote: > Hey Torquil Sørensen, > You will get the desired solution once you change "POINT_DATA 9" to > "CELL_DATA 4". > And then similarly specifying the data in each of the cell. In this case > I suppose the .vtk file for you should be- > > > # vtk DataFile Version 2.0 > Exported by getfem++ > ASCII > DATASET UNSTRUCTURED_GRID > POINTS 9 float > 0 0 0 > 0.5 0 0 > 0 0.5 0 > 0.5 0.5 0 > 1 0 0 > 1 0.5 0 > 0 1 0 > 0.5 1 0 > 1 1 0 > > CELLS 4 20 > 4 0 1 3 2 > 4 1 4 5 3 > 4 2 3 7 6 > 4 3 5 8 7 > > CELL_TYPES 4 > 9 > 9 > 9 > 9 > > CELL_DATA 4 > > > SCALARS scalarField float 1 > LOOKUP_TABLE default > 0 0 0 1 > > Cheers, > Kaushik > > > > On Tue, Sep 22, 2015 at 7:56 PM, Torquil Macdonald Sørensen > <[email protected] <mailto:[email protected]>> wrote: > > Hi! > > I have defined a 2d quadrangle mesh consisting of 2x2 elements, with > Q_1,1 basis functions in GetFEM++, and exported an example function to > ASCII VTK format. The only node at which the example function is nonzero > is the middle one. > > When I open the VTK file in Paraview, it looks as if it has used some > kind of triangle interpolation. Instead of its support being the entire > mesh, it has become zero near two opposite domain corners. In > particular, the result should have been 90-degree rotation symmetric > about the centre node. > > How do I get Paraview to display this Q_1,1 function correctly, or at > least without it seemingly being interpolated onto a triangular mesh? > > I'm using Paraview 4.3.1 and the ASCI VTK file generated by GetFEM++ is: > > # vtk DataFile Version 2.0 > Exported by getfem++ > ASCII > DATASET UNSTRUCTURED_GRID > POINTS 9 float > 0 0 0 > 0.5 0 0 > 0 0.5 0 > 0.5 0.5 0 > 1 0 0 > 1 0.5 0 > 0 1 0 > 0.5 1 0 > 1 1 0 > > CELLS 4 20 > 4 0 1 3 2 > 4 1 4 5 3 > 4 2 3 7 6 > 4 3 5 8 7 > > CELL_TYPES 4 > 9 > 9 > 9 > 9 > > POINT_DATA 9 > > > SCALARS scalarField float 1 > LOOKUP_TABLE default > 0 0 0 1 0 0 0 0 0 > > Thanks and best regards > Torquil Sørensen > > _______________________________________________ > Powered by www.kitware.com <http://www.kitware.com> > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Please keep messages on-topic and check the ParaView Wiki at: > http://paraview.org/Wiki/ParaView > > Search the list archives at: http://markmail.org/search/?q=ParaView > > Follow this link to subscribe/unsubscribe: > http://public.kitware.com/mailman/listinfo/paraview > > _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Search the list archives at: http://markmail.org/search/?q=ParaView Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/paraview
