Category Archives: mathematics

witness on Whidbey

I watched Behind the Curve (2018), a documentary about the Flat Earth movement. In the beginning, Mark Sargent says (I paraphrase), “I know the Earth is not round because I can see Seattle from here [Whidbey Island].” If I knew … Continue reading

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Scribbles: The Ensmoothening, Part III

Many of the curves in this chart have some unsightly wiggles. That’s because, when a function of degree 2 or higher tries to approximate a piecewise constant, it tends to go back and forth across the target. So here instead … Continue reading

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it’s in the literature

On a truncated icosahedron / buckyball / Telstar-style soccer ball, consider two adjacent hexagons and the two pentagons that are adjacent to both. These four faces can be removed, rotated by a right angle, and reattached, causing only a small … Continue reading

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another problem with my clothoids

I wrote: each curve hits alternate dots: first exactly, then with offsets pushing it toward the other curve. I don’t think I’ve mentioned here how the offsets work.

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clothoid weekend update

For context, see past posts in the curve-fitting category that I just created. To recap: The curves I’ve been drawing are the paths made by a point moving at constant speed at an angle which is a piecewise quadratic function … Continue reading

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un-meander

Here, each curve hits alternate dots: first exactly (above), then with offsets pushing it toward the other curve. Below is the result of eight iterations. With enough iterations, the top of ‘s’ eventually gets a more symmetrical arch, as the … Continue reading

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meander

(Previously: 2014, 2011, 2010; also, less closely related, 2015) I tried to smoothen a stroke by shifting each dot toward the Euler spiral (aka clothoid, aka Cornu spiral) determined by its four nearest neighbors. That didn’t work so well: small … Continue reading

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