| // Copyright 2011 The Closure Library Authors. All Rights Reserved. |
| // |
| // Licensed 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. |
| |
| goog.provide('goog.math.interpolator.Linear1Test'); |
| goog.setTestOnly('goog.math.interpolator.Linear1Test'); |
| |
| goog.require('goog.math.interpolator.Linear1'); |
| goog.require('goog.testing.jsunit'); |
| |
| function testLinear() { |
| // Test special case with no data to interpolate. |
| var x = []; |
| var y = []; |
| var interp = new goog.math.interpolator.Linear1(); |
| interp.setData(x, y); |
| assertTrue(isNaN(interp.interpolate(1))); |
| |
| // Test special case with 1 data point. |
| x = [0]; |
| y = [3]; |
| interp = new goog.math.interpolator.Linear1(); |
| interp.setData(x, y); |
| assertRoughlyEquals(3, interp.interpolate(1), 1e-4); |
| |
| // Test general case. |
| x = [0, 1, 3, 6, 7]; |
| y = [0, 0, 0, 0, 0]; |
| for (var i = 0; i < x.length; ++i) { |
| y[i] = Math.sin(x[i]); |
| } |
| interp = new goog.math.interpolator.Linear1(); |
| interp.setData(x, y); |
| |
| var xi = [0, 0.5, 1, 2, 3, 4, 5, 6, 7]; |
| var expected = [0, 0.4207, 0.8415, 0.4913, 0.1411, 0.0009, -0.1392, |
| -0.2794, 0.657]; |
| var result = [0, 0, 0, 0, 0, 0, 0, 0, 0]; |
| for (var i = 0; i < xi.length; ++i) { |
| result[i] = interp.interpolate(xi[i]); |
| } |
| assertElementsRoughlyEqual(expected, result, 1e-4); |
| } |
| |
| |
| function testOutOfBounds() { |
| var x = [0, 1, 2]; |
| var y = [2, 5, 4]; |
| var interp = new goog.math.interpolator.Linear1(); |
| interp.setData(x, y); |
| assertRoughlyEquals(interp.interpolate(-1), -1, 1e-4); |
| assertRoughlyEquals(interp.interpolate(4), 2, 1e-4); |
| } |
| |
| |
| function testInverse() { |
| var x = [0, 1, 3, 6, 7]; |
| var y = [0, 2, 7, 8, 10]; |
| |
| var interp = new goog.math.interpolator.Linear1(); |
| interp.setData(x, y); |
| var invInterp = interp.getInverse(); |
| |
| var xi = [0, 0.5, 1, 2, 3, 4, 5, 6, 7]; |
| var yi = [0, 1, 2, 4.5, 7, 7.3333, 7.6667, 8, 10]; |
| var resultX = [0, 0, 0, 0, 0, 0, 0, 0, 0]; |
| var resultY = [0, 0, 0, 0, 0, 0, 0, 0, 0]; |
| for (var i = 0; i < xi.length; ++i) { |
| resultY[i] = interp.interpolate(xi[i]); |
| resultX[i] = invInterp.interpolate(yi[i]); |
| } |
| assertElementsRoughlyEqual(xi, resultX, 1e-4); |
| assertElementsRoughlyEqual(yi, resultY, 1e-4); |
| } |