Java tutorial
/** * Copyright (C) 2009 - present by OpenGamma Inc. and the OpenGamma group of companies * * Please see distribution for license. */ package com.opengamma.strata.math.impl.function.special; import static org.testng.AssertJUnit.assertEquals; import java.util.function.DoubleUnaryOperator; import java.util.function.Function; import org.apache.commons.math3.random.Well44497b; import org.testng.annotations.Test; /** * Test. */ @Test public class GammaFunctionTest { private static final Well44497b RANDOM = new Well44497b(0L); private static final DoubleUnaryOperator GAMMA = new GammaFunction(); private static final Function<Double, Double> LN_GAMMA = new NaturalLogGammaFunction(); private static final double EPS = 1e-9; @Test public void test() { final double x = RANDOM.nextDouble(); assertEquals(Math.log(GAMMA.applyAsDouble(x)), LN_GAMMA.apply(x), EPS); } }