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.Thu, 21 May 2020 16:56:26 -0500Plotting surfaces over non-rectangular domainhttp://ask.sagemath.org/question/51485/plotting-surfaces-over-non-rectangular-domain/I'm wondering if we can plot a surface over non-rectangular domain.
E.g.
plot3d(lambda x, y: 2 + sin(x) + cos(y) if y < 2*pi - x else False, (x,x0,x1), (y,y0,y1))
or something. I've tried playing with the domain like
implicit_plot3d( (s,t,2+sin(s)+cos(t)), (s,0,2*pi), (t,0 2*pi - s) )
but again no dice. I'm sure I could just draw a whole bunch of polygons but I wonder if there's a better way.ShaiThu, 21 May 2020 16:56:26 -0500http://ask.sagemath.org/question/51485/Plot intersections of two relationshttp://ask.sagemath.org/question/33521/plot-intersections-of-two-relations/ How can I plot an intersection of two relations? For instance, if I have two spheres $x^2 + (y-1)^2 + (z-1)^2 = 1$ and $x^2 + y^2 + z^2 = 1$, how can I plot their intersection on a graph?slemonideMon, 23 May 2016 00:23:52 -0500http://ask.sagemath.org/question/33521/Detecting 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/