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# PLOTTING A SPHERE AND A CYLINDER    Math II    18 Sept 96
# 
# 
# We plot a sphere using spherical coordinates, and a cylinder using 
# cylindrical coordinates.
# 
# 
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# We need to use plots.
> with(plots):
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# 
# First get the cylinder.
# cylinderplot can either be called in the form
#     cylinderplot(r,theta=a..b,z=c..d);
# or in the form
#     cylinderplot([r(u,v),theta(u,v),z(u,v)],u=a..b,v=a..b);
# We use the first form here.
# 
> cylinderplot(1,theta=0..2*Pi,z=-3..3,color=red);
> cyl := cylinderplot(1,theta=0..2*Pi,z=-3..3,color=red):
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# 
# Now get the sphere.
# sphereplot can either be called in the form
#     sphereplot(r,theta=a..b,phi=c..d);
# or in the form
#     sphereplot([r(u,v),theta(u,v),phi(u,v)],u=a..b,v=c..d);
# We use the first form here.
# 
> sphereplot(2,theta=0..2*Pi,phi=0..Pi,color=blue);
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# 
# We now take just part of the sphere
> sph := sphereplot(2,theta=0..2*Pi,phi=Pi/6..5*Pi/6,color=blue):
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# 
# Plot the cylinder and sphere on the same axes:
# 
> display3d({cyl,sph},title=`Sphere and Cylinder`);
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