2014-02-06 08:10:01 +0200 | received badge | ● Student (source) |
2014-02-05 14:47:15 +0200 | asked a question | Looong computation by desolve_rk4 I'm having an issue with very long computation times for numerical solutions to DEs using desolve_rk4. It happens when computing a solution that runs off to +/- infinity. For example, the following command will do it: If I make "end_points" run from 0 to something much smaller, like 0.1, everything is okay. But I want some way to fix this behavior so that I can change the initial conditions easily for classroom demos without having to constantly change the endpoints (in an interact, for example). I also don't quite understand why it should be taking so long simply to run to infinity -- this behavior doesn't match my understanding of the RK4 algorithm. (I can understand that we might hit overflow quickly, but I would expect it should simply stop computation at that point.) Any suggestions? |
2012-09-04 15:55:43 +0200 | asked a question | Similar limits give very different behavior The following code produces the expected right answer: The answer, of course, is 2xcos(x^2). However, the following code fails to complete: Sage just thinks and thinks and does not come up with an answer. This happens on two different versions I have access to, 5.2 and 5.0. What is happening? |