Spherical pendulum 
In addition to the main simulation framework of the movement of a pendulum of this type, with the possibility of rotation of the sphere with the mouse, for a better view in space, there are frames with the trajectory in the plane (θ, θ') and in the plane (φ, φ'), both interactive (the user can, by clicking on them, choose initial values for new movements), and even one with the horizontal projection of the trajectory of the pendulum.
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In the figure below, the periodic nature of motion in the plane (θ, θ'), causing a closed curve with no self-intersections is patent. As for curves in the plane (φ, φ'), by making several choices it is possible to get an idea of the variety of possibilities.
Note1: For more information, consult the help.
