ASKSAGE: Sage Q&A Forum - Latest question feedhttp://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Sat, 14 Feb 2015 13:33:18 -0600Detecting extrema and asymptotes of (nasty) functions of two variableshttp://ask.sagemath.org/question/25829/detecting-extrema-and-asymptotes-of-nasty-functions-of-two-variables/ I have a rational function of two variables* whose extrema and limiting behavior I am intersted in. Basically I want to know what values it *cannot* contain, so, I want to know limits and asymptotics. I could do this more or less manually by plotting at zooming in, zooming out until I come up with a thesis, and then taking limits to verify, but I want to do a large number of examples at once, and I'd like to write a function that just spits out the relevant values without having me look at the plot. Any ideas? A quick search turned up no useful information on taking 2D limits.
*For those interested, the function is the j-invariant of an elliptic curve, and I'm interested in a family of such curves. It's a function of two variables as the curve is found as a particular hyperplane section of a surface, and I have a two parameter family. unit 3000-21Sat, 14 Feb 2015 13:33:18 -0600http://ask.sagemath.org/question/25829/