I once got a task from a professor when I was a graduate student to try and reproduce a figure in a book as best I could. Specifically, I had to reproduce the orbit of Mercury around the Sun. Simulating the orbit of Mercury was straight forward, but the difficult part was getting the solid lines emanating from the Sun (the origin) to the points farthest away as to show the precession of the orientation of the orbit. After asking around, I eventually got it to work and came pretty close to the figure in the book. Attached is the program. In the program I call it "perihelion." But in hindsight, I probably should've called it "aphelion."

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