On Sat, Oct 18, 2008 at 7:41 PM, henrik johansson <[EMAIL PROTECTED]> wrote: > Hi Ondrej, > > Thanks for the help. I dug a little deeper and found that the problem was > that both the LU and GaussElimination solver > could not detect zeros in the pivot elements. The problems disappeared if > the pivot elements were simplified first. > For the GE solver I could just set the simplifed argument to True in the > call to the "rref" method. > > But there are probably cases where a simplify is not enough. I do not know > if there is a more robust way of detecting if an expression is zero.
Mathematically speaking, no. But in practise, I am sure it is. Try to research some literature, and also please create a new issue for each expression, that you cannot simplify. Also we should be able to pass a custom function for simplifying (zero finding) to our matrix inversion method, so that the user can pass there his own super effective zero finder, suited for his problems. Could you please create new issues for that? > > For the circuit solver I will use the ADJ version from now on. I will keep > you informed when it is ready for release. Thanks, see also my latest email to this list. Ondrej --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
