| /* |
| * 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.math3.analysis.interpolation; |
| |
| import org.apache.commons.math3.analysis.MultivariateFunction; |
| import org.apache.commons.math3.util.FastMath; |
| import org.junit.Assert; |
| import org.junit.Test; |
| |
| /** |
| * Test case for the "microsphere projection" interpolator. |
| * |
| * @deprecated Code will be removed in 4.0. Use {@link InterpolatingMicrosphere} |
| * and {@link MicrosphereProjectionInterpolator} instead. |
| */ |
| @Deprecated |
| public final class MicrosphereInterpolatorTest { |
| /** |
| * Test of interpolator for a plane. |
| * <p> |
| * y = 2 x<sub>1</sub> - 3 x<sub>2</sub> + 5 |
| */ |
| @Test |
| public void testLinearFunction2D() { |
| MultivariateFunction f = new MultivariateFunction() { |
| public double value(double[] x) { |
| if (x.length != 2) { |
| throw new IllegalArgumentException(); |
| } |
| return 2 * x[0] - 3 * x[1] + 5; |
| } |
| }; |
| |
| MultivariateInterpolator interpolator = new MicrosphereInterpolator(); |
| |
| // Interpolating points in [-1, 1][-1, 1] by steps of 1. |
| final int n = 9; |
| final int dim = 2; |
| double[][] x = new double[n][dim]; |
| double[] y = new double[n]; |
| int index = 0; |
| for (int i = -1; i <= 1; i++) { |
| for (int j = -1; j <= 1; j++) { |
| x[index][0] = i; |
| x[index][1] = j; |
| y[index] = f.value(x[index]); |
| ++index; |
| } |
| } |
| |
| MultivariateFunction p = interpolator.interpolate(x, y); |
| |
| double[] c = new double[dim]; |
| double expected, result; |
| |
| c[0] = 0; |
| c[1] = 0; |
| expected = f.value(c); |
| result = p.value(c); |
| Assert.assertEquals("On sample point", expected, result, FastMath.ulp(1d)); |
| |
| c[0] = 0 + 1e-5; |
| c[1] = 1 - 1e-5; |
| expected = f.value(c); |
| result = p.value(c); |
| Assert.assertEquals("1e-5 away from sample point", expected, result, 1e-4); |
| } |
| |
| /** |
| * Test of interpolator for a quadratic function. |
| * <p> |
| * y = 2 x<sub>1</sub><sup>2</sup> - 3 x<sub>2</sub><sup>2</sup> |
| * + 4 x<sub>1</sub> x<sub>2</sub> - 5 |
| */ |
| @Test |
| public void testParaboloid2D() { |
| MultivariateFunction f = new MultivariateFunction() { |
| public double value(double[] x) { |
| if (x.length != 2) { |
| throw new IllegalArgumentException(); |
| } |
| return 2 * x[0] * x[0] - 3 * x[1] * x[1] + 4 * x[0] * x[1] - 5; |
| } |
| }; |
| |
| MultivariateInterpolator interpolator = new MicrosphereInterpolator(); |
| |
| // Interpolating points in [-10, 10][-10, 10] by steps of 2. |
| final int n = 121; |
| final int dim = 2; |
| double[][] x = new double[n][dim]; |
| double[] y = new double[n]; |
| int index = 0; |
| for (int i = -10; i <= 10; i += 2) { |
| for (int j = -10; j <= 10; j += 2) { |
| x[index][0] = i; |
| x[index][1] = j; |
| y[index] = f.value(x[index]); |
| ++index; |
| } |
| } |
| |
| MultivariateFunction p = interpolator.interpolate(x, y); |
| |
| double[] c = new double[dim]; |
| double expected, result; |
| |
| c[0] = 0; |
| c[1] = 0; |
| expected = f.value(c); |
| result = p.value(c); |
| Assert.assertEquals("On sample point", expected, result, FastMath.ulp(1d)); |
| |
| c[0] = 2 + 1e-5; |
| c[1] = 2 - 1e-5; |
| expected = f.value(c); |
| result = p.value(c); |
| Assert.assertEquals("1e-5 away from sample point", expected, result, 1e-3); |
| } |
| } |