Hi, I submitted a patch for Broyden schemes together with tests: http://projects.scipy.org/scipy/scipy/ticket/402 My email describing it (together with a question) is here: http://projects.scipy.org/pipermail/scipy-dev/2007-April/006979.html I won't have time for it this week and also the patch is for the svn version from a week ago, but if some of you would like to look at that, just let me know and I'll update it to the top svn. I will be glad to help the code meet SciPy's standards - just let me know if I should change anything. Thanks very much, Ondrej Certik