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Commons Math example source code file (FastSineTransformerTest.java)
The Commons Math FastSineTransformerTest.java source code/* * 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.math.transform; import org.apache.commons.math.analysis.*; import org.apache.commons.math.MathException; import junit.framework.TestCase; /** * Testcase for fast sine transformer. * <p> * FST algorithm is exact, the small tolerance number is used only * to account for round-off errors. * * @version $Revision: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $ */ public final class FastSineTransformerTest extends TestCase { /** * Test of transformer for the ad hoc data. */ public void testAdHocData() { FastSineTransformer transformer = new FastSineTransformer(); double result[], tolerance = 1E-12; double x[] = { 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0 }; double y[] = { 0.0, 20.1093579685034, -9.65685424949238, 5.98642305066196, -4.0, 2.67271455167720, -1.65685424949238, 0.795649469518633 }; result = transformer.transform(x); for (int i = 0; i < result.length; i++) { assertEquals(y[i], result[i], tolerance); } result = transformer.inversetransform(y); for (int i = 0; i < result.length; i++) { assertEquals(x[i], result[i], tolerance); } FastFourierTransformer.scaleArray(x, Math.sqrt(x.length / 2.0)); result = transformer.transform2(y); for (int i = 0; i < result.length; i++) { assertEquals(x[i], result[i], tolerance); } result = transformer.inversetransform2(x); for (int i = 0; i < result.length; i++) { assertEquals(y[i], result[i], tolerance); } } /** * Test of transformer for the sine function. */ public void testSinFunction() throws MathException { UnivariateRealFunction f = new SinFunction(); FastSineTransformer transformer = new FastSineTransformer(); double min, max, result[], tolerance = 1E-12; int N = 1 << 8; min = 0.0; max = 2.0 * Math.PI; result = transformer.transform(f, min, max, N); assertEquals(N >> 1, result[2], tolerance); for (int i = 0; i < N; i += (i == 1 ? 2 : 1)) { assertEquals(0.0, result[i], tolerance); } min = -Math.PI; max = Math.PI; result = transformer.transform(f, min, max, N); assertEquals(-(N >> 1), result[2], tolerance); for (int i = 0; i < N; i += (i == 1 ? 2 : 1)) { assertEquals(0.0, result[i], tolerance); } } /** * Test of parameters for the transformer. */ public void testParameters() throws Exception { UnivariateRealFunction f = new SinFunction(); FastSineTransformer transformer = new FastSineTransformer(); try { // bad interval transformer.transform(f, 1, -1, 64); fail("Expecting IllegalArgumentException - bad interval"); } catch (IllegalArgumentException ex) { // expected } try { // bad samples number transformer.transform(f, -1, 1, 0); fail("Expecting IllegalArgumentException - bad samples number"); } catch (IllegalArgumentException ex) { // expected } try { // bad samples number transformer.transform(f, -1, 1, 100); fail("Expecting IllegalArgumentException - bad samples number"); } catch (IllegalArgumentException ex) { // expected } } } Other Commons Math examples (source code examples)Here is a short list of links related to this Commons Math FastSineTransformerTest.java source code file: |
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