# Graph for 16.2 #22# ------------------# (Note: I evaluated the cell under this one first to enable the# 3d vector field plotter.)var('x,y,z,t')F=(z,y,-x)r=(t,sin(t),cos(t))field=plot_vector_field3d(F,(x,0,pi),(y,-1,1),(z,-1,1),colors=[(.5,1,0),(1,.5,0)],center_arrows=True)curve=parametric_plot3d(r,(t,0,pi),color='black')(field+curve).show(aspect_ratio=[1,1,1])
