[Paraview] Calculator speed

[Berk Geveci]

It will be once we update the wiki pages :-)

On Thu, Sep 11, 2008 at 1:18 PM, Weirs, V Gregory <vgweirs at sandia.gov> wrote:
>
> Dig it.
>
> Is numpy_support documented anywhere?
>
> Thanks,
> Greg
>
>
> On 9/11/08 10:31 AM, "Berk Geveci" <berk.geveci at kitware.com> wrote:
>
> (assuming you are using cvs paraview)
> In the programmable filter, you can do something like:
>
> from paraview import numpy_support
>
> input = self.GetInputDataObject(0, 0)
> ar = numpy_support.vtk_to_numpy(input.GetPointData().GetArray("pressure"))
> ar2 = ar*2
> newArray = nump7_support.numpy_to_vtk(ar2, True)
> newArray.SetName("pressure times 2")
> output = self.GetOutputDataObject(0)
> output.GetPointData().AddArray(newArray)
>
> In the future, this should look like:
> output.point_data['pressure times 2'] = input.point_data['pressure'] * 2
>
> -berk
>
>
> On Tue, Sep 9, 2008 at 2:40 PM, Tobias Brandvik <tbrandvik at gmail.com> wrote:
>> Thanks for the replies. I've got some experience with Python/NumPy so
>> any pointers on that approach would be appreciated.
>>
>> Tobias
>>
>>
>> --
>> Tobias Brandvik
>> PhD Student
>> Whittle Laboratory
>> 1 JJ Thomson Avenue
>> Cambridge CB3 0DY, UK
>>
>> On Tue, Sep 9, 2008 at 2:51 PM, Berk Geveci <berk.geveci at kitware.com>
>> wrote:
>>> The array calculator does not use Python but it is slow nevertheless.
>>> Actually, this could be done much faster using Python/NumPy. This is
>>> currently possible but hard to do (complicated API). We are working on
>>> an easier-to-use interface.  If you are adventurous, I can give you
>>> some pointers. Otherwise, C++ custom filter is the way to go.
>>>
>>> -berk
>>>
>>> On Tue, Sep 9, 2008 at 8:58 AM, Tobias Brandvik <tbrandvik at gmail.com>
>>> wrote:
>>>> Hi,
>>>>
>>>> I've written a CFD solver that uses Paraview in parallel mode with
>>>> hdf5/xdmf. Currently, the application writes out the primary variables
>>>> and lets the user calculate any desired secondary variables using the
>>>> calculator. However, this procedure is very slow -- it seems to be an
>>>> order of magnitude faster to calculate the data in the solver itself
>>>> and have Paraview read it from disk. I suspect this is because the
>>>> calculator expressions get translated to python code, but I might also
>>>> be doing something wrong.
>>>>
>>>> Am I correct in thinking that the easiest way to fix this would be to
>>>> write a custom filter in C++?
>>>>
>>>> Cheers,
>>>> Tobias
>>>>
>>>> --
>>>> Tobias Brandvik
>>>> PhD Student
>>>> Whittle Laboratory
>>>> 1 JJ Thomson Avenue
>>>> Cambridge CB3 0DY, UK
>>>> _______________________________________________
>>>> ParaView mailing list
>>>> ParaView at paraview.org
>>>> http://www.paraview.org/mailman/listinfo/paraview
>>>>
>>>
>>
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