[Paraview] Calculator Filter -- Gradient

[Berk Geveci]

I am not sure that I understand. Are Q1 and Q2 vectors? Are you trying
to divide the component by component?

2010/9/13 Aurélien Marsan <aur.marsan at gmail.com>:
> Hello,
>
> In order to calculate a new scalar (here for a multiblockdataset)
>
> pdi = self.GetInput()
>
> pdo = self.GetOutput()
>
> pdo.ShallowCopy(pdi)
>
> for block in output[0]:
>
> if block.GetNumberOfPoints() != 0:
>
> array = block.PointData['Q1'] / block.PointData['Q2']
>
> block.PointData.append(array, 'newQ')
>
> For a new vector, I would like someone to explain a simple way to do that.
> (without many transpose, ravel, etc...)
> Knowing that it does not work with array =
> numpy.array([block.PointData['Q1'], block.PointData['Q2'],
> block.PointData['Q3']]) / block.PointData['Q4']
> because of a problem of dimensions.
>
> Regards,
>
> A.Marsan
>
> 2010/9/10 <DParker at chromalloy.com>
>>
>> I have a couple of questions about using the Programmable Filter. I have
>> imported Tecplot dataset with the following data: coordsX, coordsY, coordsZ,
>> Q1, Q2, Q3, Q4, Q5.
>>
>> How would I create a new data array that is Q2^2+Q3^2+Q4^2?
>>
>> How would I create a new vector data array (similar to
>> Q2*iHat+Q3*jHat+Q4*kHat in the Calculator Filter)?
>>
>>
>>
>>
>> From:        David E DeMarle <dave.demarle at kitware.com>
>> To:        DParker at chromalloy.com
>> Cc:        paraview at paraview.org
>> Date:        09/10/2010 01:24 PM
>> Subject:        Re: [Paraview] Calculator Filter -- Gradient
>> Sent by:        paraview-bounces at paraview.org
>> ________________________________
>>
>>
>> On Fri, Sep 10, 2010 at 1:10 PM,  <DParker at chromalloy.com> wrote:
>> > I have two somewhat related questions:
>> >
>> > 1. Is it possible to calculate a gradient vector using the calculator
>> > filter?
>>
>> No. The calculator filter does only element wise (cell by cell or
>> point by point) computations. To compute the gradient you need
>> information from neighboring elements.
>>
>> >
>> > 2. Is it possible to define a new data array using a Python script
>> > without
>> > the calculator filter? Currently, I am using several Calculator Filters
>> > to
>> > calculate CFD flow variables from the conservative variables. I use a
>> > Python
>> > script to create the Calculator Filters, but I'm wondering if I can
>> > avoid
>> > the Calculator Filter and directly generate new data arrays for
>> > plotting.
>> >
>>
>> Not with a python script (under the python shell) since that runs on
>> the client and can't really manipulate the data (which lives on the
>> server) directly. However, the python programmable filter runs on the
>> server, and with that you can create new arrays, and access
>> neighboring elements as well.
>> See http://www.paraview.org/Wiki/Python_Programmable_Filter for examples.
>>
>> > David Parker
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>
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>
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