I would like to use Sage to draw colormap plots of spherical functions on the surface of spheres. I want to produce something like this example.
Are such plots currently possible in Sage, or using optional toolkits? I would like to have a color plots of arbitrary functions f(theta,phi).
Moreover, is it possible to have contour plots of such functions as well?
I don't think the Sage 3d graphics allow very much flexibility for coloring currently. Here is an example showing how to color a 3d surface using matplotlib, though: http://stackoverflow.com/a/6543777/1200039
Something like this:
var('x,y')
cm = colormaps.spring
cf = lambda x,y: (sin(x) + cos(y)) % 1
spherical_plot3d(1,(x,0,4*pi/2),(y,0,pi),color=(cf,cm)).show(aspect_ratio=(1,1,1))
The look is not as smooth as one would like with the default number of plot points.
For a smoother look, increase the number of plot points.
sage: cm = colormaps.spring
sage: f = lambda x, y: 1
sage: cf = lambda x, y: (sin(x) + cos(y)) % 1
sage: p = spherical_plot3d(f, (0, 2*RDF.pi()), (0, RDF.pi()), color=(cf, cm), plot_points=200)
sage: p.show(aspect_ratio=1, viewer='threejs')
Higher values of plot_points increase resolution (but also time to display the plot).
Try for example plot_points=400 or even plot_points=800...
Asked: 2013-01-30 12:05:04 +0200
Seen: 1,360 times
Last updated: Apr 08 '19
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If it is possible using scipy and matplotlib, then you can use those directly in sage. I don't think it is possible by using some Sage function directly.