[Insight-users] Using paraview to view magnitude of deformation field?

[motes motes]

I have created a deformation field after running the
BSplineWarping1.cxx example on a 2D image. I have then followed:

http://www.itk.org/pipermail/insight-users/2008-June/026264.html

but just with my .mhd file instead. The result in paraview is this
deformation field:

http://img4.imageshack.us/img4/2471/39113360.png


Now I would like to create a histogram of the magnitude of the
deformations.  I have therefore selected: Filters->Data
Analysis->Histogram. Under display I have selected:
GlyphVector_average(Magnitude) which gives me this:


http://img59.imageshack.us/img59/1350/knowndeformationmagnitu.png

But i don't understand the above histogram. Is the x-axis the
magnitude in pixels and the y-axis the number of vectors with that
magnitude? Since the image is 512*512 I would expected to get a
histogram for 512*512=262144 vectors. But that does not quite add up
from the above screenshot.




I assume I would get the same result using paraview compared to the
steps described here:

http://www.itk.org/pipermail/insight-users/2006-May/017872.html