import mir.math.common: log;
import mir.test: shouldApprox;

0.0.rayleighLPDF.shouldApprox == -double.infinity;
0.5.rayleighLPDF.shouldApprox == log(0.4412485);
1.0.rayleighLPDF.shouldApprox == log(0.6065307);
2.0.rayleighLPDF.shouldApprox == log(0.2706706);

// Can also provide scale parameter
0.5.rayleighLPDF(2.0).shouldApprox == log(0.1211541);
1.0.rayleighLPDF(2.0).shouldApprox == log(0.2206242);
4.0.rayleighLPDF(2.0).shouldApprox == log(0.1353353);