| /* |
| * 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.math4.transform; |
| |
| import java.util.function.DoubleUnaryOperator; |
| |
| import org.junit.Assert; |
| import org.junit.Test; |
| |
| import org.apache.commons.math3.analysis.function.Sin; |
| |
| /** |
| * Tests for {@link TransformUtils}. |
| */ |
| public class TransformUtilsTest { |
| private static final Sin SIN_FUNCTION = new Sin(); |
| private static final DoubleUnaryOperator SIN = x -> SIN_FUNCTION.value(x); |
| |
| @Test(expected = TransformException.class) |
| public void testSampleWrongBounds() { |
| TransformUtils.sample(SIN, Math.PI, 0.0, 10); |
| } |
| |
| @Test(expected = TransformException.class) |
| public void testSampleNegativeNumberOfPoints() { |
| TransformUtils.sample(SIN, 0.0, Math.PI, -1); |
| } |
| |
| @Test(expected = TransformException.class) |
| public void testSampleNullNumberOfPoints() { |
| TransformUtils.sample(SIN, 0.0, Math.PI, 0); |
| } |
| |
| @Test |
| public void testSample() { |
| final int n = 11; |
| final double min = 0.0; |
| final double max = Math.PI; |
| final double[] actual = TransformUtils.sample(SIN, min, max, n); |
| for (int i = 0; i < n; i++) { |
| final double x = min + (max - min) / n * i; |
| Assert.assertEquals("x = " + x, Math.sin(x), actual[i], 1e-15); |
| } |
| } |
| } |