[Jprogramming] Eigen values in J

[Michal D.]

Hi All,

I have been trying to get J to compute the eigen values & vectors of a
matrix.  I've come across
http://www.jsoftware.com/jwiki/Essays/Eigenvaluesbut none of the
algorithms there seem stable on my input matrix and the
lapack package doesn't seem to work on 64-bit J.  I laboriously exported
the matrix to a .csv and then hacked up a C++ program that computes the
eigen values using eigen (
http://eigen.tuxfamily.org/index.php?title=Main_Page) which had no problem
with computing the eigen values.

What is the current state-of-the-art in eigen values in J?  Should I just
downgrade to 32-bit J and use the lapack package?

Cheers,

Mike


Ps. There is nothing I like better than generating random input data using
J.  What took pages of Haskell and TCL was boiled down to 7 clear lines of
J.  WOW =)