Ah, found my problem. I was naming the output from the first calculators staring with a digit, 01_x for example. This was fine for displaying etc but does not seem to be valid for the next calculator. I have fixed this now, please ignore my previous message.
Regards, Michael On Thu, Dec 10, 2009 at 3:35 PM, Michael Rapson <[email protected]> wrote: > 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
