| /* |
| * 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.legacy.analysis.interpolation; |
| |
| import org.apache.commons.math4.legacy.analysis.TrivariateFunction; |
| import org.apache.commons.math4.legacy.exception.DimensionMismatchException; |
| import org.apache.commons.math4.legacy.exception.MathIllegalArgumentException; |
| import org.apache.commons.math4.legacy.core.jdkmath.AccurateMath; |
| import org.junit.Assert; |
| import org.junit.Test; |
| |
| /** |
| * Test case for the {@link TricubicInterpolator tricubic interpolator}. |
| */ |
| public final class TricubicInterpolatorTest { |
| /** |
| * Test preconditions. |
| */ |
| @Test |
| public void testPreconditions() { |
| double[] xval = new double[] {3, 4, 5, 6.5}; |
| double[] yval = new double[] {-4, -3, -1, 2.5}; |
| double[] zval = new double[] {-12, -8, -5.5, -3, 0, 2.5}; |
| double[][][] fval = new double[xval.length][yval.length][zval.length]; |
| |
| @SuppressWarnings("unused") |
| TrivariateFunction tcf = new TricubicInterpolator().interpolate(xval, yval, zval, fval); |
| |
| double[] wxval = new double[] {3, 2, 5, 6.5}; |
| try { |
| tcf = new TricubicInterpolator().interpolate(wxval, yval, zval, fval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (MathIllegalArgumentException e) { |
| // Expected |
| } |
| double[] wyval = new double[] {-4, -1, -1, 2.5}; |
| try { |
| tcf = new TricubicInterpolator().interpolate(xval, wyval, zval, fval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (MathIllegalArgumentException e) { |
| // Expected |
| } |
| double[] wzval = new double[] {-12, -8, -9, -3, 0, 2.5}; |
| try { |
| tcf = new TricubicInterpolator().interpolate(xval, yval, wzval, fval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (MathIllegalArgumentException e) { |
| // Expected |
| } |
| double[][][] wfval = new double[xval.length - 1][yval.length][zval.length]; |
| try { |
| tcf = new TricubicInterpolator().interpolate(xval, yval, zval, wfval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (DimensionMismatchException e) { |
| // Expected |
| } |
| wfval = new double[xval.length][yval.length - 1][zval.length]; |
| try { |
| tcf = new TricubicInterpolator().interpolate(xval, yval, zval, wfval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (DimensionMismatchException e) { |
| // Expected |
| } |
| wfval = new double[xval.length][yval.length][zval.length - 1]; |
| try { |
| tcf = new TricubicInterpolator().interpolate(xval, yval, zval, wfval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (DimensionMismatchException e) { |
| // Expected |
| } |
| } |
| |
| @Test |
| public void testIsValid() { |
| double[] xval = new double[] {3, 4, 5, 6.5}; |
| double[] yval = new double[] {-4, -3, -1, 2.5}; |
| double[] zval = new double[] {-12, -8, -5.5, -3, 0, 2.5}; |
| double[][][] fval = new double[xval.length][yval.length][zval.length]; |
| |
| TricubicInterpolatingFunction tcf = new TricubicInterpolator().interpolate(xval, yval, zval, fval); |
| |
| // Valid. |
| Assert.assertTrue(tcf.isValidPoint(4, -3, -8)); |
| Assert.assertTrue(tcf.isValidPoint(5, -3, -8)); |
| Assert.assertTrue(tcf.isValidPoint(4, -1, -8)); |
| Assert.assertTrue(tcf.isValidPoint(5, -1, -8)); |
| Assert.assertTrue(tcf.isValidPoint(4, -3, 0)); |
| Assert.assertTrue(tcf.isValidPoint(5, -3, 0)); |
| Assert.assertTrue(tcf.isValidPoint(4, -1, 0)); |
| Assert.assertTrue(tcf.isValidPoint(5, -1, 0)); |
| |
| // Invalid. |
| Assert.assertFalse(tcf.isValidPoint(3.5, -3, -8)); |
| Assert.assertFalse(tcf.isValidPoint(4.5, -3.1, -8)); |
| Assert.assertFalse(tcf.isValidPoint(4.5, -2, 0.1)); |
| Assert.assertFalse(tcf.isValidPoint(4.5, 0, -3.5)); |
| Assert.assertFalse(tcf.isValidPoint(4.1, -1, -10)); |
| } |
| |
| /** |
| * Test for a plane. |
| * <p> |
| * f(x, y, z) = 2 x - 3 y - 4 z + 5 |
| * </p> |
| */ |
| @Test |
| public void testPlane() { |
| double[] xval = new double[] {3, 4, 5, 6.5}; |
| double[] yval = new double[] {-4, -3, -1, 2, 2.5}; |
| double[] zval = new double[] {-12, -8, -5.5, -3, 0, 2.5}; |
| |
| // Function values |
| TrivariateFunction f = new TrivariateFunction() { |
| @Override |
| public double value(double x, double y, double z) { |
| return 2 * x - 3 * y - 4 * z + 5; |
| } |
| }; |
| |
| double[][][] fval = new double[xval.length][yval.length][zval.length]; |
| |
| for (int i = 0; i < xval.length; i++) { |
| for (int j = 0; j < yval.length; j++) { |
| for (int k = 0; k < zval.length; k++) { |
| fval[i][j][k] = f.value(xval[i], yval[j], zval[k]); |
| } |
| } |
| } |
| |
| TrivariateFunction tcf = new TricubicInterpolator().interpolate(xval, |
| yval, |
| zval, |
| fval); |
| double x; |
| double y; |
| double z; |
| double expected; |
| double result; |
| |
| x = 4; |
| y = -3; |
| z = 0; |
| expected = f.value(x, y, z); |
| result = tcf.value(x, y, z); |
| Assert.assertEquals("On sample point", |
| expected, result, 1e-15); |
| |
| x = 4.5; |
| y = -1.5; |
| z = -4.25; |
| expected = f.value(x, y, z); |
| result = tcf.value(x, y, z); |
| Assert.assertEquals("Half-way between sample points (middle of the patch)", |
| expected, result, 1e-14); |
| } |
| |
| /** |
| * Sine wave. |
| * <p> |
| * f(x, y, z) = a cos [ω z - k<sub>y</sub> x - k<sub>y</sub> y] |
| * </p> |
| * with A = 0.2, ω = 0.5, k<sub>x</sub> = 2, k<sub>y</sub> = 1. |
| */ |
| @Test |
| public void testWave() { |
| double[] xval = new double[] {3, 4, 5, 6.5}; |
| double[] yval = new double[] {-4, -3, -1, 2, 2.5}; |
| double[] zval = new double[] {-12, -8, -5.5, -3, 0, 4}; |
| |
| final double a = 0.2; |
| final double omega = 0.5; |
| final double kx = 2; |
| final double ky = 1; |
| |
| // Function values |
| TrivariateFunction f = new TrivariateFunction() { |
| @Override |
| public double value(double x, double y, double z) { |
| return a * AccurateMath.cos(omega * z - kx * x - ky * y); |
| } |
| }; |
| |
| double[][][] fval = new double[xval.length][yval.length][zval.length]; |
| for (int i = 0; i < xval.length; i++) { |
| for (int j = 0; j < yval.length; j++) { |
| for (int k = 0; k < zval.length; k++) { |
| fval[i][j][k] = f.value(xval[i], yval[j], zval[k]); |
| } |
| } |
| } |
| |
| TrivariateFunction tcf = new TricubicInterpolator().interpolate(xval, |
| yval, |
| zval, |
| fval); |
| |
| double x; |
| double y; |
| double z; |
| double expected; |
| double result; |
| |
| x = 4; |
| y = -3; |
| z = 0; |
| expected = f.value(x, y, z); |
| result = tcf.value(x, y, z); |
| Assert.assertEquals("On sample point", |
| expected, result, 1e-14); |
| |
| x = 4.5; |
| y = -1.5; |
| z = -4.25; |
| expected = f.value(x, y, z); |
| result = tcf.value(x, y, z); |
| Assert.assertEquals("Half-way between sample points (middle of the patch)", |
| expected, result, 1e-1); // XXX Too high tolerance! |
| } |
| } |