NormalRandomNumberGeneratorTest.java

/**
 * Copyright (C) 2009 - present by OpenGamma Inc. and the OpenGamma group of companies
 *
 * Please see distribution for license.
 */
package com.opengamma.strata.math.impl.random;

import static com.opengamma.strata.collect.TestHelper.assertThrowsIllegalArg;
import static org.testng.AssertJUnit.assertEquals;

import java.util.List;

import org.testng.annotations.Test;

import cern.jet.random.engine.MersenneTwister64;

/**
 * Test {@link NormalRandomNumberGenerator}.
 */
@Test
public class NormalRandomNumberGeneratorTest {

  private static final NormalRandomNumberGenerator GENERATOR = new NormalRandomNumberGenerator(0, 1);

  public void test_array() {
    double[] result = GENERATOR.getVector(10);
    assertEquals(result.length, 10);
  }

  public void test_list() {
    List<double[]> result = GENERATOR.getVectors(10, 50);
    assertEquals(result.size(), 50);
    for (double[] d : result) {
      assertEquals(d.length, 10);
    }
  }

  public void test_invalid() {
    assertThrowsIllegalArg(() -> new NormalRandomNumberGenerator(0, -1));
    assertThrowsIllegalArg(() -> new NormalRandomNumberGenerator(0, -1, new MersenneTwister64()));
    assertThrowsIllegalArg(() -> new NormalRandomNumberGenerator(0, 1, null));
    assertThrowsIllegalArg(() -> GENERATOR.getVectors(-1, 4));
    assertThrowsIllegalArg(() -> GENERATOR.getVectors(1, -5));
  }

}