| /* |
| * 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.analysis.function; |
| |
| import org.apache.commons.math4.analysis.UnivariateFunction; |
| import org.apache.commons.math4.analysis.differentiation.DerivativeStructure; |
| import org.apache.commons.math4.analysis.function.Sigmoid; |
| import org.apache.commons.math4.exception.DimensionMismatchException; |
| import org.apache.commons.math4.exception.NullArgumentException; |
| import org.junit.Assert; |
| import org.junit.Test; |
| |
| /** |
| * Test for class {@link Sigmoid}. |
| */ |
| public class SigmoidTest { |
| private final double EPS = Math.ulp(1d); |
| |
| @Test |
| public void testSomeValues() { |
| final UnivariateFunction f = new Sigmoid(); |
| |
| Assert.assertEquals(0.5, f.value(0), EPS); |
| Assert.assertEquals(0, f.value(Double.NEGATIVE_INFINITY), EPS); |
| Assert.assertEquals(1, f.value(Double.POSITIVE_INFINITY), EPS); |
| } |
| |
| @Test |
| public void testDerivative() { |
| final Sigmoid f = new Sigmoid(); |
| final DerivativeStructure f0 = f.value(new DerivativeStructure(1, 1, 0, 0.0)); |
| |
| Assert.assertEquals(0.25, f0.getPartialDerivative(1), 0); |
| } |
| |
| @Test |
| public void testDerivativesHighOrder() { |
| DerivativeStructure s = new Sigmoid(1, 3).value(new DerivativeStructure(1, 5, 0, 1.2)); |
| Assert.assertEquals(2.5370495669980352859, s.getPartialDerivative(0), 5.0e-16); |
| Assert.assertEquals(0.35578888129361140441, s.getPartialDerivative(1), 6.0e-17); |
| Assert.assertEquals(-0.19107626464144938116, s.getPartialDerivative(2), 6.0e-17); |
| Assert.assertEquals(-0.02396830286286711696, s.getPartialDerivative(3), 4.0e-17); |
| Assert.assertEquals(0.21682059798981049049, s.getPartialDerivative(4), 3.0e-17); |
| Assert.assertEquals(-0.19186320234632658055, s.getPartialDerivative(5), 2.0e-16); |
| } |
| |
| @Test |
| public void testDerivativeLargeArguments() { |
| final Sigmoid f = new Sigmoid(1, 2); |
| |
| Assert.assertEquals(0, f.value(new DerivativeStructure(1, 1, 0, Double.NEGATIVE_INFINITY)).getPartialDerivative(1), 0); |
| Assert.assertEquals(0, f.value(new DerivativeStructure(1, 1, 0, -Double.MAX_VALUE)).getPartialDerivative(1), 0); |
| Assert.assertEquals(0, f.value(new DerivativeStructure(1, 1, 0, -1e50)).getPartialDerivative(1), 0); |
| Assert.assertEquals(0, f.value(new DerivativeStructure(1, 1, 0, -1e3)).getPartialDerivative(1), 0); |
| Assert.assertEquals(0, f.value(new DerivativeStructure(1, 1, 0, 1e3)).getPartialDerivative(1), 0); |
| Assert.assertEquals(0, f.value(new DerivativeStructure(1, 1, 0, 1e50)).getPartialDerivative(1), 0); |
| Assert.assertEquals(0, f.value(new DerivativeStructure(1, 1, 0, Double.MAX_VALUE)).getPartialDerivative(1), 0); |
| Assert.assertEquals(0, f.value(new DerivativeStructure(1, 1, 0, Double.POSITIVE_INFINITY)).getPartialDerivative(1), 0); |
| } |
| |
| @Test(expected=NullArgumentException.class) |
| public void testParametricUsage1() { |
| final Sigmoid.Parametric g = new Sigmoid.Parametric(); |
| g.value(0, null); |
| } |
| |
| @Test(expected=DimensionMismatchException.class) |
| public void testParametricUsage2() { |
| final Sigmoid.Parametric g = new Sigmoid.Parametric(); |
| g.value(0, new double[] {0}); |
| } |
| |
| @Test(expected=NullArgumentException.class) |
| public void testParametricUsage3() { |
| final Sigmoid.Parametric g = new Sigmoid.Parametric(); |
| g.gradient(0, null); |
| } |
| |
| @Test(expected=DimensionMismatchException.class) |
| public void testParametricUsage4() { |
| final Sigmoid.Parametric g = new Sigmoid.Parametric(); |
| g.gradient(0, new double[] {0}); |
| } |
| |
| @Test |
| public void testParametricValue() { |
| final double lo = 2; |
| final double hi = 3; |
| final Sigmoid f = new Sigmoid(lo, hi); |
| |
| final Sigmoid.Parametric g = new Sigmoid.Parametric(); |
| Assert.assertEquals(f.value(-1), g.value(-1, new double[] {lo, hi}), 0); |
| Assert.assertEquals(f.value(0), g.value(0, new double[] {lo, hi}), 0); |
| Assert.assertEquals(f.value(2), g.value(2, new double[] {lo, hi}), 0); |
| } |
| } |