| /* |
| * 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.exception.DimensionMismatchException; |
| import org.apache.commons.math3.exception.MathIllegalArgumentException; |
| import org.apache.commons.math3.util.FastMath; |
| import org.apache.commons.math3.analysis.BivariateFunction; |
| import org.junit.Assert; |
| import org.junit.Test; |
| |
| /** |
| * Test case for the smoothing bicubic interpolator. |
| * |
| * @deprecated To be removed in 4.0 (see MATH-1166). |
| */ |
| @Deprecated |
| public final class SmoothingPolynomialBicubicSplineInterpolatorTest { |
| /** |
| * Test preconditions. |
| */ |
| @Test |
| public void testPreconditions() { |
| double[] xval = new double[] {3, 4, 5, 6.5, 7.5}; |
| double[] yval = new double[] {-4, -3, -1, 2.5, 3}; |
| double[][] zval = new double[xval.length][yval.length]; |
| |
| BivariateGridInterpolator interpolator = new SmoothingPolynomialBicubicSplineInterpolator(0); |
| |
| @SuppressWarnings("unused") |
| BivariateFunction p = interpolator.interpolate(xval, yval, zval); |
| |
| double[] wxval = new double[] {3, 2, 5, 6.5}; |
| try { |
| p = interpolator.interpolate(wxval, yval, zval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (MathIllegalArgumentException e) { |
| // Expected |
| } |
| |
| double[] wyval = new double[] {-4, -3, -1, -1}; |
| try { |
| p = interpolator.interpolate(xval, wyval, zval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (MathIllegalArgumentException e) { |
| // Expected |
| } |
| |
| double[][] wzval = new double[xval.length][yval.length + 1]; |
| try { |
| p = interpolator.interpolate(xval, yval, wzval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (DimensionMismatchException e) { |
| // Expected |
| } |
| wzval = new double[xval.length - 1][yval.length]; |
| try { |
| p = interpolator.interpolate(xval, yval, wzval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (DimensionMismatchException e) { |
| // Expected |
| } |
| wzval = new double[xval.length][yval.length - 1]; |
| try { |
| p = interpolator.interpolate(xval, yval, wzval); |
| Assert.fail("an exception should have been thrown"); |
| } catch (DimensionMismatchException e) { |
| // Expected |
| } |
| } |
| |
| /** |
| * Test of interpolator for a plane. |
| * <p> |
| * z = 2 x - 3 y + 5 |
| */ |
| @Test |
| public void testPlane() { |
| BivariateFunction f = new BivariateFunction() { |
| public double value(double x, double y) { |
| return 2 * x - 3 * y + 5 |
| + ((int) (FastMath.abs(5 * x + 3 * y)) % 2 == 0 ? 1 : -1); |
| } |
| }; |
| |
| BivariateGridInterpolator interpolator = new SmoothingPolynomialBicubicSplineInterpolator(1); |
| |
| double[] xval = new double[] {3, 4, 5, 6.5, 7.5}; |
| double[] yval = new double[] {-4, -3, -1, 2, 2.5, 3.5}; |
| double[][] zval = new double[xval.length][yval.length]; |
| for (int i = 0; i < xval.length; i++) { |
| for (int j = 0; j < yval.length; j++) { |
| zval[i][j] = f.value(xval[i], yval[j]); |
| } |
| } |
| |
| BivariateFunction p = interpolator.interpolate(xval, yval, zval); |
| double x, y; |
| double expected, result; |
| |
| x = 4; |
| y = -3; |
| expected = f.value(x, y); |
| result = p.value(x, y); |
| Assert.assertEquals("On sample point", expected, result, 2); |
| |
| x = 4.5; |
| y = -1.5; |
| expected = f.value(x, y); |
| result = p.value(x, y); |
| Assert.assertEquals("half-way between sample points (middle of the patch)", expected, result, 2); |
| |
| x = 3.5; |
| y = -3.5; |
| expected = f.value(x, y); |
| result = p.value(x, y); |
| Assert.assertEquals("half-way between sample points (border of the patch)", expected, result, 2); |
| } |
| |
| /** |
| * Test of interpolator for a paraboloid. |
| * <p> |
| * z = 2 x<sup>2</sup> - 3 y<sup>2</sup> + 4 x y - 5 |
| */ |
| @Test |
| public void testParaboloid() { |
| BivariateFunction f = new BivariateFunction() { |
| public double value(double x, double y) { |
| return 2 * x * x - 3 * y * y + 4 * x * y - 5 |
| + ((int) (FastMath.abs(5 * x + 3 * y)) % 2 == 0 ? 1 : -1); |
| } |
| }; |
| |
| BivariateGridInterpolator interpolator = new SmoothingPolynomialBicubicSplineInterpolator(4); |
| |
| double[] xval = new double[] {3, 4, 5, 6.5, 7.5, 8}; |
| double[] yval = new double[] {-4, -3, -2, -1, 0.5, 2.5}; |
| double[][] zval = new double[xval.length][yval.length]; |
| for (int i = 0; i < xval.length; i++) { |
| for (int j = 0; j < yval.length; j++) { |
| zval[i][j] = f.value(xval[i], yval[j]); |
| } |
| } |
| |
| BivariateFunction p = interpolator.interpolate(xval, yval, zval); |
| double x, y; |
| double expected, result; |
| |
| x = 5; |
| y = 0.5; |
| expected = f.value(x, y); |
| result = p.value(x, y); |
| Assert.assertEquals("On sample point", expected, result, 2); |
| |
| x = 4.5; |
| y = -1.5; |
| expected = f.value(x, y); |
| result = p.value(x, y); |
| Assert.assertEquals("half-way between sample points (middle of the patch)", expected, result, 2); |
| |
| x = 3.5; |
| y = -3.5; |
| expected = f.value(x, y); |
| result = p.value(x, y); |
| Assert.assertEquals("half-way between sample points (border of the patch)", expected, result, 2); |
| } |
| } |