| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.numbers.gamma; |
| |
| import org.junit.jupiter.api.Assertions; |
| import org.junit.jupiter.api.Test; |
| |
| /** |
| * Tests for {@link InverseErf}. |
| */ |
| public class InverseErfTest { |
| @Test |
| public void testErfInvNaN() { |
| Assertions.assertTrue(Double.isNaN(InverseErf.value(-1.001))); |
| Assertions.assertTrue(Double.isNaN(InverseErf.value(+1.001))); |
| Assertions.assertTrue(Double.isNaN(InverseErf.value(Double.NaN))); |
| } |
| |
| @Test |
| public void testErfInvInfinite() { |
| Assertions.assertTrue(Double.isInfinite(InverseErf.value(-1))); |
| Assertions.assertTrue(InverseErf.value(-1) < 0); |
| Assertions.assertTrue(Double.isInfinite(InverseErf.value(+1))); |
| Assertions.assertTrue(InverseErf.value(+1) > 0); |
| } |
| |
| @Test |
| public void testErfInv() { |
| for (double x = -5.9; x < 5.9; x += 0.01) { |
| final double y = Erf.value(x); |
| final double dydx = 2 * Math.exp(-x * x) / Math.sqrt(Math.PI); |
| Assertions.assertEquals(x, InverseErf.value(y), 1.0e-15 / dydx); |
| } |
| } |
| } |