Trouble with Eigenvalues



>>>>> "Ben" == Ben Blomberg <bblomberg at mail.bradley.edu> writes:

    Ben> Hello all,



    Ben> I am working on a project with maxima and I have generated a
    Ben> 21x21 matrix. The off diagonal elements have values from .1
    Ben> to 1e-6. The on diagonal elements have values from 300 to
    Ben> 500. I am trying to use maxima to find the eigenvalues of
    Ben> this matrix however it takes several minutes to do the
    Ben> calculations and then never displays a result, it
    Ben> continuously says "reading output". Does maxima have trouble
    Ben> with?matrices?this large? Has anyone else had a similar
    Ben> trouble and if so what did you do?



    Ben> Its worth noting that mathematica can find the eigenvalues to
    Ben> this matrix in about one minute.

You didn't say how you were calculating the eigenvalues.  What were
you using?  If I load(lapack), and use dgeev on a 21x21 matrix, I get
the eigenvalues in just 20 ms on my machine. (Loading lapack takes
a few minutes though.)

Ray