I will check it. Thanks.
-Zhanping On Sat, Apr 11, 2009 at 12:15 AM, Takuya OSHIMA <[email protected]>wrote: > Hi Jie, Renato, > > There had been a bug until ParaView 3.4 that led the volume of a wedge > to have been miscalculated as a negated volume of a tetrahedron. > http://www.paraview.org/pipermail/paraview/2008-August/009246.html > http://paraview.org/Bug/view.php?id=7588 > > The bug has been fixed with the recent CVS versions. > > I can confirm that the bug also affects volume calculations of clipped > hexahedral meshes as well by Jie's test.vtk. If I try the .vtk with a > CVS version and follow Jie's procedure I get a volume of 4.95177e-13 > which is closer to the analytic value of 5.23599e-13. However if I > revert the bugfix (revert vtkWedge.cxx from the current revision 1.7 > to ParaView 3.4's 1.5) I get the identical value with what Jie got, > 3.32862e-13. > > Takuya OSHIMA, Ph.D. > Faculty of Engineering, Niigata University > 8050 Ikarashi-Ninocho, Nishi-ku, Niigata, 950-2181, JAPAN > > > From: Renato Elias <[email protected]> > Subject: Re: [Paraview] Questions regarding: volume calculation, xyplot > along a curve and tensor calculation > Date: Fri, 10 Apr 2009 22:39:36 -0300 > > > It seems rounding errors... try to scale your model at least 100x to see > > what happens... > > > > Just to reforce Jie Xu's problem. It's not the first time the Integrate > > Variable presents issues in volume calculations. Take a look: > > > http://markmail.org/message/67dkxpypfodylfnr#query:volume%20integration%20paraview%20renato+page:1+mid:67dkxpypfodylfnr+state:results > > > > In my case, I don't remember if the problem was solved.... > > > > I tried to find my dataset to test it again but I haven't found (yet).... > > :-( > > > > Renato. > > > > > > > > On Fri, Apr 10, 2009 at 4:30 PM, Jie Xu <[email protected]> wrote: > > > >> Hi Berk, > >> > >> Thanks for looking at my questions. > >> > >> 1) I attached a sample data set: test.vtk, and the screenshot of my > >> paraview window, from which you can see that the clip is created at > >> (0,0,0) with radius of 50e-6, and the calculated volume is > >> 3.32862e-13, which is much less than what it should be. > >> (Interestingly, in this specific case, the calculated volume is about > >> 2/pi times the real volume.) > >> > >> 2) Thanks for letting me know. > >> > >> 3) Unfortunately, I have no experience with Python. Now I am trying to > >> see if I can use matlab to do the tensor calculates and modify the vtk > >> file readable by paraview. > >> > >> Regards, > >> Jie > >> > >> On Thu, Apr 9, 2009 at 1:51 PM, Berk Geveci <[email protected]> > >> wrote: > >> > Hi Jie, > >> > > >> >> 1) Volume calculation: > >> >> I found that the "integrate variables" over a sphere clip never gives > >> >> the correct volume. For example, I tried to use a very simple > geometry > >> >> and a very fine mesh (a 200x200x200 micron cube with 2 micron cube > >> >> elements), and use paraview to generate a sphere clip that has radius > >> >> of 50 micron in the center of that cube, then I apply the "integrate > >> >> variables" filter to the clip and show the "Cell Data", it gives a > >> >> volume of 4.78818e-13 instead of 5.236e-13, which is 4/3*pi*r^3. The > >> >> discrepancy is so large that it just cannot be due to the coarseness > >> >> of the mesh. Different mesh and different size of clips gives > >> >> different discrepancies, and I cannot find any obvious relationship > >> >> between the paraview-calculated volume and the real volume. > >> > > >> > When I create a 100^3 wavelet and clip it with a sphere of radius 20, > >> > I am getting a volume of 33447.5 which is pretty close to the analytic > >> > value of 33510.3. Can you send me a dataset that demonstrates this > >> > problem? > >> > > >> >> 2) X-Y plot: how can I do a xyplot of a scalar along a curved line? > >> >> For example, if I have the pressure field data from a > >> >> flow-around-a-cylinder case, I want to plot the pressure along the > >> >> surface of the cylinder as a function of angle or arc length. > >> > > >> > You can't, yet. I am working on that feature for the next release. > >> > > >> >> 3) tensor calculation: I have the pressure field and velocity field > >> >> calculated from a CFD tool (Transat in my case), how do I calculate > >> >> stress tensors at each point from P V field in paraview? > >> > > >> > Let me ask a question back : do you have any Python knowledge? We are > >> > working on making this really simple but currently the array > >> > calculator is too limited and cannot produce tensors. However, this is > >> > doable using the programmable filter. > >> > > >> > -berk > _______________________________________________ > 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 > -- Zhanping Liu, PhD Kitware, Inc. 28 Corporate Drive Clifton Park, NY 12065-8662 Phone: 518-371-3971 x 138 http://www.zhanpingliu.org
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