Problems with lsquares an wxMaxima



>>>>> "Andreas" == Andreas Goebel <a-goebel at gmx.de> writes:

    Andreas> Hi,
    Andreas> I?m having problems with lsquares and the lsquares_estimates command.

    Andreas> The first problem is a wxMaxima problem: The function doesn?t return the
    Andreas> focus to wxMaxima. I have to press abort, then I get the results. This
    Andreas> doesn?t happen when an exact solution with solve is found.

    Andreas> The second problem seems to be a lsquares problem: In the sample (see
    Andreas> attachment) I want to fit a logistic growth function to the given data.

    Andreas> I get an empty result. If I remove just one data pair, I get fine
    Andreas> results (no matter which data pair I remove).

    Andreas> I would very much like to know if there are known bugs and limitations
    Andreas> of that command. I have some more problems with it (all of them related
    Andreas> to logistic or other growth functions).

Looks like maxima is getting stuck trying to find an exact solution.
(At least I can see maxima is running solve.)

Perhaps this is a bug in lsquares_estimates.

You probably want just a numerical solution, so
lsquares_estimates_approximate, lbfgs, or minpack_lsquares can
probably provide you with the numerical solution.

Ray