143.sagews

# Graph for 15.3 #28
# -------------------

# Probably the easiest way to plot these cylinders is as parametric surfaces.
# The black circle is the region of integration in the xy-plane.
# (Note r = 1 in this picture.)

var('u,v')
region = sage.plot.plot.circle((0,0),1,rgbcolor=(0,0,0),fill=True)
vertical = parametric_plot3d((sin(u),cos(u),v),(u,0,2*pi),(v,-2,2),color='red',opacity=.5,mesh=True)
horizontal = parametric_plot3d((v,sin(u),cos(u)),(u,0,2*pi),(v,-2,2),color='blue',opacity=.5,mesh=True)
(horizontal + vertical + region).show(aspect_ratio=[1,1,1])