[Paraview] choppy derivatives

[Berk Geveci]

I wonder if this is because of the multiple celldata -> point data
conversions. Do you have an example dataset you can share?

On Sun, Mar 28, 2010 at 1:45 AM, Peter Brady <petertbrady at gmail.com> wrote:
> Hello list,
>
> I have a 3D dataset with a Temperature field.  My goal is to insert a sphere
> source and determine the tangential temperature gradient on the surface of
> the sphere at various zenith angles.  The data is output from the code as
> cell data.  Here is the way I'm doing this (through pvpython)
>
> 1.  Apply CellDataToPointData
> 2.  Apply ComputeDerivatives (to get the 'Scalar Gradient')
> 3.  Apply another CellDataToPointData (to turn the derivatives into point
> data)
> 4.  Resample the data from step 3 with my sphere source.
> 5.  Use a programmable filter to combine the xyz derivatives appropriately.
>
> The data is reasonable but it's fairly choppy.  When I look at dT/dx, dT/dy,
> and dT/dz (before I project them onto the sphere surface), and plot them at
> a particular zenith angle around the azimuth of the drop, dTdx and dTdy are
> very smooth but dT/dz is fairly choppy (especially above the equator of the
> drop).  If I expand my sphere to a place where there's not a lot going on
> dT/dz seems to calm down.  Is there a way to smooth dT/dz in the location of
> interest or should I try to write my own derivatives filter to make them
> smoother?  Any thoughts?
>
> Thanks,
> Peter.
>
> _______________________________________________
> 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
>
>