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mimo
25 lines
534 B
JavaScript
25 lines
534 B
JavaScript
/**
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* Returns a pair of independent and normally distributed (zero mean, variance 1) random numbers.
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* Uses the Polar-Rejection method.
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*/
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function randomNormal2D()
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{
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let s, a, b;
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do
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{
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a = 2 * Math.random() - 1;
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b = 2 * Math.random() - 1;
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s = a * a + b * b;
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} while (s>=1 || s==0);
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s = Math.sqrt(-2 * Math.log(s) / s);
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return [a * s, b * s];
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}
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/**
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* Return a random element of the source array
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*/
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function pickRandom(source)
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{
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return source.length ? source[Math.floor(source.length * Math.random())] : undefined;
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}
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