On Thu, Mar 26, 2009 at 07:17:14PM -0700, Ondrej Certik wrote: > But even when this is fixed --- it will still be a sympy integral. So > what do you want lambdify to do with it? keep it as a sympy integral > and you will then call .evalf() yourself on it, or make it somehow > call scipy.integrate? I believe the best option is to patch sympy to > create an option in .evalf(use_scipy=True), that would lambdify the > argument and then call scipy integrate on the argument.
> But try sympy's integration, if it's <1000, it *may* be fast enough. > If it's not, let's implement use_scipy, so that it can use scipy > automatically. That will be good-enough for now. > Btw, I am myself surprised, that we can do this integral already: > In [16]: i > Out[16]: > ∞ > ⌠ > ⎮ 2 > ⎮ -x > ⎮ ℯ dx > ⌡ > -∞ > In [17]: i.doit() > Out[17]: > ⎽⎽⎽ > ╲╱ π > In [18]: i.evalf() > Out[18]: 1.77245385090552 > In [19]: i.doit().evalf() > Out[19]: 1.77245385090552 OK, I guess this relates to my other problem (the subs not working). > > I would like 'Out[4]' to have x substituted :). I can see why it is hard > > (sympy is probably not tracking that the integration variable does not > > depend on x), but I'd still like it :). > Yes, sure. I think it doesn't work yet, I found some related issues: > http://code.google.com/p/sympy/issues/detail?id=951 > http://code.google.com/p/sympy/issues/detail?id=987 > anyway, I made a new one set to fix in the next release, as this is a > high priority and I think it's easy to fix: > http://code.google.com/p/sympy/issues/detail?id=1351 Cool, great. > Let's make a deal --- I'll fix this for you and you'll review my > patches that are holding off the sympy release: > http://code.google.com/p/sympy/issues/list?q=label:NeedsReview > :) > Then we can release sympy *and* have it fixed. Sounds like a deal. I'll start right away (I wil have to run soon, but I'l try to do it tongiht, coming back from the restaurant -- I am in Berkeley, with some people you know). Anyway, your code reads like a book, so it will be a piece of cake :). Gaël --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
