[vtkusers] Multi-Input and Math on Data

[Charl P. Botha]

On Thu, 26 Aug 2004 17:38:17 -0400, Stewart Dickson <dicksonsp at ornl.gov> wrote:
> I wish to visualize a derived 480x480x480 scalar data field:
> entropy = pressure / density ^ 1.33333
> 
> I have the vtkNetCDFHDFReader library which is distributed with ASPECT
> <http://www.aspect-sdm.org>  Therefore, I can read the data files into Vtk.
> 
> Is there a library in Vtk to allow one to do exponentiation and division
> on the output of two vtkNetCDFHDFReaders?

I'm assuming the vtkNetCDFHDFReaders output vtkImageData types.  In
that case, you can use vtkImageMathematics[1] to perform the division,
but raising to a power is currently not directly supported (unless I'm
overlooking something).  The right way would be be to adapt the
vtkImageMathematics class to support this - this would be
straight-forward modification.  A kludge would be to decompose your
exponentiation into exp and log, both operations that are supported by
vtkImageMathematics.

-- 
charl p. botha http://cpbotha.net/ http://visualisation.tudelft.nl/