[Paraview] Python + ParaView

Nico Schlömer nico.schloemer at gmail.com
Thu Jun 16 09:24:47 EDT 2011 

> See the manual for the syntax.

Where can I find that? The ParaView User's Guide
<www.paraview.org/files/v1.6/ParaViewUsersGuide.PDF> isn't too verbose
on any of that.
The Wiki, on the other hand, seems to contain a fair amount of
examples. Specifically, I've looked at
<http://www.paraview.org/Wiki/Python_Programmable_Filter> to see about
programmable filters.

Unfortunately, this hasn't gotten me very far, as I'm lacking
understanding of the entities used in the examples.
Questions I asked myself were:
 * What do I need to do to fetch my point data:
self.GetPolyDataInput()? self.GetInputDataObject(0, 0)? Or simply
self.GetInput()?
 * How do I access point data then?
 * Do I have to create a new vector and feed this into some sort of
output thing?

Is there a documentation as to what methods are available for those types?

The input file is Exodus, if that makes any difference.

If there's a tutorial for this kind of stuff, I'll be happy to go
through it; otherwise I'd appreciate your help here.

Cheers,
Nico






On Wed, Jun 8, 2011 at 6:17 PM, David E DeMarle
<dave.demarle at kitware.com> wrote:
> Also the standard calculator does have conditionals, there just isn't a
> button corresponding to them on the UI. See the manual for the syntax.
> David E DeMarle
> Kitware, Inc.
> R&D Engineer
> 28 Corporate Drive
> Clifton Park, NY 12065-8662
> Phone: 518-371-3971 x109
>
>
> On Wed, Jun 8, 2011 at 12:16 PM, David E DeMarle <dave.demarle at kitware.com>
> wrote:
>>
>> The python programmable filter (and the easier to use python programmable
>> calculator variant of that) will get you beyond all of those limitations.
>> David E DeMarle
>> Kitware, Inc.
>> R&D Engineer
>> 28 Corporate Drive
>> Clifton Park, NY 12065-8662
>> Phone: 518-371-3971 x109
>>
>>
>> On Wed, Jun 8, 2011 at 12:11 PM, Nico Schlömer <nico.schloemer at gmail.com>
>> wrote:
>>>
>>> > If you want to do arbitrary arithmetic, you will have to first
>>> > generate the array using something like a "Calculator" filter and then
>>> > color using the generated array.
>>>
>>> Oh, if I remember correctly I did look into this before, and found the
>>> calculator filter too limited on the arithmetics that you could
>>> perform. Is it still the case that you have a set of like ten
>>> functions (add, multiply, sine, cosine,...) to mix and match? I need
>>> to to something like
>>>
>>> for x in data_values:
>>>    if x[0] > 0 and x[1] > 0
>>>        return bla
>>>    elseif ...
>>>
>>> -- atan2() that is.
>>>
>>>
>>> > Yes, RGBPoints defines the mapping between scalar and color. It's a
>>> > list of 4 tuples (scalar, r, g, b), repeated sequentially.
>>>
>>> Hm, I'll look into it. Where's the proper spot for documentation of this?
>>>
>>> Cheers,
>>> Nico
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Wed, Jun 8, 2011 at 5:25 PM, Utkarsh Ayachit
>>> <utkarsh.ayachit at kitware.com> wrote:
>>> > Magnitude corresponds to the magnitude of a vector, so yes, it takes
>>> > the square root.
>>> >
>>> > If you want to do arbitrary arithmetic, you will have to first
>>> > generate the array using something like a "Calculator" filter and then
>>> > color using the generated array.
>>> >
>>> > Yes, RGBPoints defines the mapping between scalar and color. It's a
>>> > list of 4 tuples (scalar, r, g, b), repeated sequentially.
>>> >
>>> > Utkarsh
>>> >
>>> > On Wed, Jun 8, 2011 at 11:19 AM, Nico Schlömer
>>> > <nico.schloemer at gmail.com> wrote:
>>> >> Thanks for the hints.
>>> >>
>>> >> The Trace function in indeed quite useful in that it get you where you
>>> >> want to be. When looking at the code there's still a lot of me to
>>> >> understand though, the GetLookupTableForArray() call seems to be
>>> >> crucial for example.
>>> >>
>>> >>  * The VectorMode='Magnitude' parameter seems to be responsible for
>>> >> merging the two components into one scalar, but I'm not quite sure how
>>> >> this is done: with a sqrt() or without? Is is possible to customize
>>> >> this? I'd like to have something like ATAN2 there as well.
>>> >>
>>> >>  * Is the RGBPoints=[0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0],
>>> >> parameter responsible for the colormap?
>>> >>
>>> >> Cheers,
>>> >> Nico
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >> On Wed, Jun 8, 2011 at 3:13 PM, Utkarsh Ayachit
>>> >> <utkarsh.ayachit at kitware.com> wrote:
>>> >>> The following wiki page talks about how to color using arrays:
>>> >>>
>>> >>> http://www.paraview.org/Wiki/ParaView/Python_Scripting#Representations_and_Views
>>> >>>
>>> >>> The easiest way to figure out Python code equivalents is to use the
>>> >>> Trace functionality to generate python trace files for actions
>>> >>> performed in the GUI (accessible from Tools menu). You "Start Trace",
>>> >>> do a set of actions and then "Stop Trace" and you should be able to
>>> >>> view the resulting Python code.
>>> >>>
>>> >>> Utkarsh
>>> >>>
>>> >>>
>>> >>>
>>> >>> On Wed, Jun 8, 2011 at 9:05 AM, Nico Schlömer
>>> >>> <nico.schloemer at gmail.com> wrote:
>>> >>>> Hi,
>>> >>>>
>>> >>>> I'm just taking first steps with ParaView's Python interface and
>>> >>>> figured out so far that
>>> >>>>
>>> >>>> ================ *snip* ================
>>> >>>> exodusReader = ExodusIIReader( FileName="solution.e" )
>>> >>>> Show( exodusReader )
>>> >>>> Render()
>>> >>>> ================ *snap* ================
>>> >>>>
>>> >>>> would plot the mesh that is stored in the ExodusII file solution.e,
>>> >>>> and that can play around with GetActiveView() to adjust camera
>>> >>>> angles
>>> >>>> and such.
>>> >>>>
>>> >>>> What I haven't found out though is how to plot actual point data. I
>>> >>>> get
>>> >>>>
>>> >>>>
>>> >>>>>>> exodusReader.PointData[:]
>>> >>>> [Array: GlobalNodeId, Array: PedigreeNodeId, Array: A, Array: psi,
>>> >>>> Array: thickness]
>>> >>>>
>>> >>>> and l'm looking at the 2-component array "psi". For example, I'd
>>> >>>> like
>>> >>>> to do something like
>>> >>>>
>>> >>>>    res =  sqrt( component1**2 + component2**2 )
>>> >>>>
>>> >>>> and have res[:] rendered on the mesh with a certain color map.
>>> >>>>
>>> >>>> Any hints?
>>> >>>>
>>> >>>> Cheers,
>>> >>>> Nico
>>> >>>> _______________________________________________
>>> >>>> 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
>>
>
>

More information about the ParaView mailing list