Tag Archives: computing

Spooky nulls in an ArrayList

I had a crash reported for one of my Android applications. Thankfully that includes a stack trace, because I would never have found this bug without it. I learned something new about concurrently accessing an ArrayList.

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A Gentleman’s Orthonormal Basis Rotation

So you need to draw curved and bent pipe-tube-things. You can make a straight section with two rings of points; just orient one ring like so, the other ring like so, and draw triangles between them. For a curve, just … Continue reading

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Iterating Over a Triangulation in Java

Say you’ve got some points in a plane, and you’re fixin’ to triangulate them. Specifically, you’re going to generate the Delaunay triangulation with an incremental algorithm, and then of course you’re going to want the triangles and/or segments. Now say … Continue reading

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Rendering Twisty Thingies

I’ve got a program called Twist Flux. It features an array of twisty, bendy… thingies. I found a way to render twisty shapes which appear to have volume without going so far as to use 3D models of twisted rods.

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Quick and Easy Gaussian Random Numbers

Generating random numbers which fit a normal distribution is essential for stochastic optimization, especially for continuous evolutionary algorithms. For high-quality results the weapon of choice is the Box–Muller transform. It’s a little expensive; it involves exponents and trigonometry and such. … Continue reading

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