[vtkusers] vtkMath::Jacobi question

[Gerald Dalley]

I am using vtkMath::Jacobi to do some eigen analysis for me.  Whenever I
call that method, I get an "Error extracting eigenfunctions" error message.
I've looked in the source and the message is generated by a conditional
whose comment says "//// this is NEVER called".

Without digging into the source to understand the intricacies of the
algorithm, it looks like this condition will "often" happen rather than
"never": the outer loop preceeding the conditional terminates when
i=VTK_MAX_ROTATIONS and the conditional check is for i>=VTK_MAX_ROTATIONS,
so unless the loop exits early through one of its break statements, that
test will fail.

Is this error message a real one, and if so, what does it really mean?

--Gerald Dalley
  dalleyg at dma.org