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17 package org.apache.commons.math4.legacy.fitting.leastsquares;
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19 import org.apache.commons.statistics.distribution.NormalDistribution;
20 import org.apache.commons.statistics.distribution.ContinuousDistribution;
21 import org.apache.commons.rng.UniformRandomProvider;
22 import org.apache.commons.rng.sampling.ObjectSampler;
23 import org.apache.commons.rng.sampling.UnitSphereSampler;
24 import org.apache.commons.rng.simple.RandomSource;
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29 public class RandomCirclePointGenerator implements ObjectSampler<double[]> {
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31 private final ContinuousDistribution.Sampler cX;
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33 private final ContinuousDistribution.Sampler cY;
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35 private final UnitSphereSampler sampler;
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37 private final double radius;
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46 public RandomCirclePointGenerator(double x,
47 double y,
48 double radius,
49 double xSigma,
50 double ySigma) {
51 final UniformRandomProvider rng = RandomSource.XO_SHI_RO_256_PP.create();
52 this.radius = radius;
53 cX = NormalDistribution.of(x, xSigma).createSampler(rng);
54 cY = NormalDistribution.of(y, ySigma).createSampler(rng);
55 sampler = UnitSphereSampler.of(rng, 2);
56 }
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58 @Override
59 public double[] sample() {
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61 final double[] xy = sampler.sample();
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63 xy[0] = radius * xy[0] + cX.sample();
64 xy[1] = radius * xy[1] + cY.sample();
65 return xy;
66 }
67 }