[Paraview] Programmable filter from external python program

[Simon Couture]

Thank you for your help Paul. I think I narrowed down my problem. Your example
(and also my own) indeed work when executed from the paraview GUI's python
shell. However, when I try to run your example from an external python shell
(outside the paraview GUI), this is what I get:

In [5]: from paraview.simple import *
paraview version 3.98.1

In [6]: paraview
Out[6]: <module 'paraview' from
'/raid/usr/local/lib/paraview-3.98/site-packages/paraview/__init__.py'>

In [7]: Sphere1 = Sphere( guiName="Sphere1" )

In [8]: ProgrammableFilter1 = ProgrammableFilter( guiName="ProgrammableFilter1",
RequestUpdateExtentScript='', RequestInformationScript='', Script="input =
self.GetInput()\noutput = self.GetOutput()\noutput.ShallowCopy(input)\n\nnp =
output.GetNumberOfPoints()\n\narray =
vtk.vtkFloatArray()\narray.SetName('newArray')\narray.SetNumberOfTuples(np)\nfor
i in range(np):\n    array.SetValue(i,
i)\n\noutput.GetPointData().AddArray(array)\n", PythonPath='' )

In [9]: UpdatePipeline()
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named paraview

In [10]: paraview
Out[10]: <module 'paraview' from
'/raid/usr/local/lib/paraview-3.98/site-packages/paraview/__init__.py'>

In [11]: ProgrammableFilter1.PointData.GetNumberOfArrays()
Out[11]: 0

I make sure that my python path contains all the directories that are present in
the paraview GUI's python shell session. Indeed I can type 'import paraview' or
'import paraview.simple' (as above) with no problem, but somehow I get this
weird ImportError when updating the pipeline with the programmable filter. Any
ideas on how to get to the bottom of this? This is on Linux CentOS and using
either python 2.6 or 2.7 yields this error.

Simon


Quoting Paul Edwards <paul.m.edwards at gmail.com>:

> Are you sure you are updating?  This works for me in pvpython:
>
> >>> from paraview.simple import *
> paraview version 4.1.0-243-gd6a42b6
> >>> Sphere1 = Sphere( guiName="Sphere1" )
> >>>
> >>> ProgrammableFilter1 = ProgrammableFilter(
> guiName="ProgrammableFilter1", RequestUpdateExtentScript='',
> RequestInformationScript='', Script="input = self.GetInput()\noutput =
> self.GetOutput()\noutput.ShallowCopy(input)\n\nnp =
> output.GetNumberOfPoints()\n\narray =
>
vtk.vtkFloatArray()\narray.SetName('newArray')\narray.SetNumberOfTuples(np)\nfor
> i in range(np):\n    array.SetValue(i,
> i)\n\noutput.GetPointData().AddArray(array)\n", PythonPath='' )
> >>> UpdatePipeline()
> >>> ProgrammableFilter1.PointData.GetNumberOfArrays()
> 2
>
> Regards,
> Paul
>
>
>
> On 6 March 2014 01:31, Simon Couture <simon-2.couture at polymtl.ca> wrote:
>
> > Hi everyone,
> >
> > I am trying to use paraview from an external python program where I import
> > paraview.simple and mostly use python code generated by Paraview's trace
> > tool
> > to accomplish what I want. In general it works well, but in one instance I
> > need
> > to generate a new data array from my source/reader, and as far as I know,
> > the
> > programmable filter is the only way to do this (the actual PointData
> > arrays of
> > the sources are not directly visible/editable through the python shell).
> > Now
> > when I try to execute the python code that I get from trace to insert a
> > programmable filter with a given script, the PointData array that the
> > programmable filter's script is supposed to create is not created (and it
> > does
> > work when I create the programmable filter using the Paraview GUI).
> >
> > To be more clear, here is the python code that I run (cutting out camera
> > and
> > rendering commands):
> >
> > mysource = AVSUCDReader( FileNames=['/home/myfile.inp'] )
> >
> > mysource.PointArrayStatus = []
> > mysource.CellArrayStatus = []
> >
> > RenderView1 = GetRenderView()
> > DataRepresentation3 = Show()
> > ProgrammableFilter1 = ProgrammableFilter()
> > DataRepresentation4 = Show()
> > ProgrammableFilter1.RequestUpdateExtentScript = ''
> > ProgrammableFilter1.PythonPath = ''
> > ProgrammableFilter1.RequestInformationScript = ''
> > ProgrammableFilter1.Script = "pdi = self.GetInput()\nnbpoints =
> > pdi.GetNumberOfPoints()\ninput_pointdata =
> > pdi.GetPointData().GetArray('data')
> > [... the rest of my script here]"
> >
> > After running this in either the paraview python shell or from an external
> > python program, if I do for instance:
> >
> > ProgrammableFilter1.PointData.GetNumberOfArrays()
> >
> > I get 0 meaning that no PointData array was created, whereas if the same
> > programmable filter is created in the paraview GUI, I would get 1. Please
> > note
> > that I am not using the Copy Arrays option of the programmable filter.
> >
> > Has anyone successfully used the programmable filter from a python script?
> >
> > _______________________________________________
> > 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
> >
>