[vtkusers] Vtkpcastatistics eigenvectors

[David Thompson]

> I'm trying to use the Vtkpcastatistics filter for an eigenvectors  
> analysis. But i'm not sure where the corresponding eigenvalues and  
> eigenvectors are stored in the output of the filter. Does someone on  
> the list have some experience with the filter?
>
Hi Stefan,

There are some links to PDF reports on the various statistics engines  
here:

   http://www.kitware.com/InfovisWiki/index.php/Statistics_Engines

See the Documentation section near the bottom of the page.

The PCA statistics filter (with the Learn option turned on, the  
default) takes a vtkTable containing observations and generates (on  
the filter's second output) a multiblock dataset whose first block is  
a vtkTable containing means and centered sums of co-moments; and whose  
following blocks (assuming you have also turned on the filter's Derive  
option) are tables laid out as shown here:

   http://paraview.org/Wiki/Statistical_analysis

Specifically, http://paraview.org/Wiki/File:PCADerivedData.png shows  
how the eigenvalues and eigenvectors are reported.

	David