[sage-support] Programming animation
Hiya! Is there a relatively simple way to get a point to animate a point through a cycle keeping in mind my low programming skills ((like adding a wait between iterations?) ? I made this video with stop animation and an animated gif but it was a real pain. http://www.youtube.com/watch?v=2ddeHKk9ssg Now I really want to show how the parameter moves through 3d curves (and then surfaces) e.g. I would like to animate a point through the first curve on: http://sagenb.org/home/pub/4212/ Thanks for any help. Linda -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Numerical approximation of symbolic coefficients
I've got these polynomials in two variables, `x`, and `u`. The polynomials are low degree (eight at the moment), but I'm working symbolically, so they print exactly: ..+ 314069483520)*sqrt(3) - 80295755776*x + 4831838208)/(1953125*x^63 - 73828125*x^61... All I would really like is to see these displayed with approximate coefficients, and to compute their roots. First attempt: loop through each term and try to n() the coefficient. Madness. Second attempt: leave SR and work in `Polynomial`s over RR. This works for display purposes, but once I have an MPolynomial_polydict object, I can't figure out how to get the roots (potentially in either variable). I can go back to SR, take the roots, and then.. go back to Polynomials? Is there a better way to go about it? I feel like I'm reinventing the wheel. -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] Numerical approximation of symbolic coefficients
First attempt: loop through each term and try to n() the coefficient. Madness. Based on a suggestion Mike Hansen once gave me -- http://ask.sagemath.org/question/411/substituting-expressions-for-numbers -- I tend to use subclasses of Converter when I need to do something like this, so as not to get lost in the madness. :^) Something like: from sage.symbolic.expression_conversions import Converter class Evaluator(Converter): def arithmetic(self, ex, operator): return reduce(operator, map(self, ex.operands())) def pyobject(self, ex, obj): return ex.n() sage: E = Evaluator() sage: var(u x) (u, x) sage: q = ((314069483520)*sqrt(3/(sin(u+2)))*u - 80295755776*x + 4831838208)/(1953125*x^63) sage: q 33554432/1953125*(9360*sqrt(3)*u*sqrt(1/sin(u + 2)) - 2393*x + 144)/x^63 sage: E(q) 17.17986918398*(16211.99555884469*u*(1/sin(u + 2.0))^0.5 - 2393.0*x + 144.0)/x^63.0 Doug -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
