Protip: Any two-axis graph can be re-labeled 'coordinates of the ants crawling across my screen as a function of time'.

"Polar/Cartesian", by Randall Munroe, licensed under Creative Commons Attribution-NonCommercial 2.5 License

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Protip: Any two-axis graph can be re-labeled 'coordinates of the ants crawling across my screen as a function of time'.