Dear Sven, Thank you for that answer. I would have struggled to find that post and both do exactly what I need.
Something that I noticed when applying step 4: > 4) Use Calculator #2 on AppendAttributes1 to take difference (eg h1-h0). If h1 and h0 are extracted as a single component of a vector, eg velocity_0, I get an error when applying this calculator: ERROR: In /home/kitware/ParaView-3.6/ParaView3/VTK/Common/vtkFunctionParser.cxx, line 1629 vtkFunctionParser (0x3376110): Syntax error: operator expected; see position 2 ERROR: In /home/kitware/ParaView-3.6/ParaView3/VTK/Common/vtkFunctionParser.cxx, line 1629 vtkFunctionParser (0x3376110): Syntax error: operator expected; see position 2 Warning: In /home/kitware/ParaView-3.6/ParaView3/VTK/Graphics/vtkArrayCalculator.cxx, line 394 vtkArrayCalculator (0x3036ec0): An error occured when parsing the calculator's function. See previous errors. I have seen these errors on Linux paraview 3.6.1 and 3.2.1 as well as Mac 3.4. Interestingly enough if I set up the initial two calculators with a scalar field, e.g. pressure, it works fine and I can later swop the pressures to velocity_0 with out any problem. (In order to test this I used a single .vtk file with a vector velocity a scalar pressure and made a copy of the file copy of the file. Once the inputs were swopped I confirmed that the difference between the velocities in the files was zero.) I was surprised that taking the velocities directly failed, but specifying the pressures first and swopping seems to be a good work around. Thanks for the help! Michael On Wed, Dec 9, 2009 at 2:15 PM, Sven Buijssen <[email protected]> wrote: > Hi Michael, > > Your first question has been discussed before, e.g., here: > http://markmail.org/message/jon3wyz3ve2rzza5 > > Regarding your second question you're looking for the ParaView filter Resample > with Dataset. It takes two inputs which will be your coarse and refined grid. > See the filter's help for more details. > > Sven > > > ----- Original Message ----- > From: Michael Rapson <[email protected]> > To: [email protected] > Sent: 12/09/09 12:41:12 > Subject: [Paraview] using integrate variables between two filters >> Hi all, >> >> I use Paraview to post process results from finite element simulations >> and find it very useful. There is however, one thing that seems >> feasible but I cannot find out how to do in Paraview and I would >> appreciate it if someone could tell me whether it is possible. >> >> I write data from my simulation to file as .vtk with a number of >> variables at each mesh location (say x velocity, y velocity and >> pressure). In Paraview I can load the file, compute result = >> velocity_X - velocity_Y using the calculator and then integrate >> variables to get the integral of velocity_X - velocity_Y on the mesh. >> This is obviously not a very useful result in general, what I really >> want is to compute velocity_X_simulation_1 - velocity_X_simulation_2, >> where simulation 1 and 2 share the same mesh but some different >> parameters. I can use a similar method to the one described above as >> long as the data from both simulations is stored in the same .vtk >> file, but is it possible to load two .vtk files into a single >> pipeline, or to access data across pipelines for the integrate >> variables method? >> >> An even more optimistic question, if the two simulations are run on >> meshes that exist on the same domain (i.e. region in space) but have a >> different set of nodes, say the mesh for simulation 2 is refined once >> more than the mesh from simulation 1, is it possible for Paraview to >> interpolate data from the less refined mesh to the more refined mesh >> in order to compute velocity_X_simulation_1 - velocity_X_simulation_2 >> and integrate? >> >> The first scenario seems technically feasible, if it has been offered >> in Paraview. Alternatively, are there specialized programs that can >> read two .vtk files and combine their variables into a single .vtk >> file? The second is more optimistic and couldn't be done without >> explicitly interpolating the results from one mesh to the other. I >> have found the Group Datasets filter, but this does not seem to quite >> do it (the data sets are marked (partial) once grouped and calculating >> differences fails). >> >> Thank you for any ideas about how I could achieve this, and also >> confirming whether it can be done in Paraview or if I should make >> another plan will help me to move forward. >> >> Regards, >> Michael >> _______________________________________________ >> 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 >> >> Follow this link to subscribe/unsubscribe: >> http://www.paraview.org/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 Follow this link to subscribe/unsubscribe: http://www.paraview.org/mailman/listinfo/paraview
