On Thu, Oct 23, 2008 at 6:45 AM, henrik johansson <[EMAIL PROTECTED]> wrote: >> > 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? > > Maybe it is better to just add a warning in the docstring to the matrix > inversion and solve_linear_system functions > that the solver might have problems if the matrix not simplified.
Indeed. Could you please prepare a patch? We'll merge it. > Otherwise > there will be unnecessary overhead if the > expressions are already simple enough. And file all occasions where simplify > cannot detect a zero as a bug. Right. That's why we should allow the user to pass his own simplifying functions. I think there will always be cases when simplify cannot do it, so that when the user can pass it's own zero finder, he can fix that easily. And let's report all failing cases as bugs to simplify. We'll then judge on case by case basis if simplify should handle it or not and how it should be approached. Thanks, Ondrej --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected] 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 -~----------~----~----~----~------~----~------~--~---
