[Paraview] extract location of minimum

[Eelco van Vliet]

Hi David,

Thanks for you suggestion, I got much closer to what I want, but not quite
yet. I have the feeling I need one slight extra hint :)

To obtain the position of a minimun value I now do the script below: I get
the mimimum value first with MinMax, then I Threshold the original data on a
range between min and 0.9*min (the minimum values are negative), then I use
the calculator to get the x and y position of this range, and then I use the
DescriptiveStatitics filter to get the average mean of the position. I can
even use Fetch again to obtain the data, but now the very last step: how to
I get the mean data itself ? Sorry, I just don't understand how that
data.objects exactly work, and there is not much assessible documentation on
it.

I hope you can give me one last hint

Regards

Eelco

      mm=MinMax(Uzcomponent)
      mm.Operation="MIN"
      mindata=sm.Fetch(Uzcomponent,mm,mm)
      mindata.GetPointData().GetNumberOfArrays()
      a0 = mindata.GetPointData().GetArray(1)
      uzname=a0.GetName()
      uzmin=a0.GetTuple1(0)
      print "minimum of %s found: %g\n "%(uzname,uzmin)

      Threshold1 = Threshold(Uzcomponent)
      Threshold1.Scalars=['POINTS',uzname]
      Threshold1.ThresholdRange=[uzmin,0.9*uzmin]

      CalcPos = Calculator()
      CalcPos.AttributeMode = 'point_data'
      CalcPos.Function = 'iHat*coordsX+jHat*coordsY+kHat*coordsZ'
      CalcPos.ResultArrayName = 'MinPos'

      DescriptiveStatistics1 = DescriptiveStatistics()
      DescriptiveStatistics1.VariablesofInterest = ['MinPos']
      statistics=sm.Fetch(DescriptiveStatistics1)




On Thu, Feb 10, 2011 at 7:00 PM, David E DeMarle
<dave.demarle at kitware.com>wrote:

> The min max filter unfortunately doesn't keep track of which tuple and
> processor it found the min in so you can't get back to the particular
> point or cell it came from.
>
> Instead of using fetch and minmax, try using a values selection. Set
> the value to be that minimum value. Once you extract the selection and
> fetch it to the client, you get a copy of the actuall cell(s)/point(s)
> that have the minimum value and you can query them directly for their
> spatial location.
>
> David E DeMarle
> Kitware, Inc.
> R&D Engineer
> 28 Corporate Drive
> Clifton Park, NY 12065-8662
> Phone: 518-371-3971 x109
>
>
>
> On Thu, Feb 10, 2011 at 12:13 PM, Eelco van Vliet <eelcovv at gmail.com>
> wrote:
> > Dear Paraviewers,
> >
> > I would like to extract the location of a minimum value from a data set
> in
> > pvbatch
> >
> > I were able to find the value of the minimum with
> >
> >
> >
> >
> >        mm=MinMax(Uzcomponent)
> >        mm.Operation="MIN"
> >        mindata=sm.Fetch(Uzcomponent,mm,mm)
> >        mindata.GetPointData().GetNumberOfArrays()
> >        a0 = mindata.GetPointData().GetArray(1)
> >        a1 = mindata.GetScalar()
> >        print "name 1: ", a0.GetName()
> >        print "tuple1: ", a0.GetTuple1(0)
> >
> > Here, a0.GetTyple1 give me the value of the minimum
> >
> > However: How do I find the location of this value ?
> >
> > Any hint appriciate!
> >
> > Regards
> >
> > Eelco
> >
> >
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