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Android example source code file (BeatTimingsAdjuster.java)
The BeatTimingsAdjuster.java Android example source code/* * Copyright (C) 2008 Google Inc. * * 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. */ package com.google.clickin2dabeat; import java.util.ArrayList; /** * Adjusts the times for the beat targets using a linear least-squares fit. */ public class BeatTimingsAdjuster { private double[] adjustedBeatTimes; public void setRawBeatTimes(ArrayList<Integer> rawBeatTimes) { double[] beatTimes = new double[rawBeatTimes.size()]; for (int i = 0; i < beatTimes.length; i++) { beatTimes[i] = rawBeatTimes.get(i); } adjustedBeatTimes = new double[beatTimes.length]; double[] beatNumbers = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; double n = beatNumbers.length; // Some things can be computed once and never computed again double[] beatNumbersXNumbers = multiplyArrays(beatNumbers, beatNumbers); double sumOfBeatNumbersXNumbers = sum(beatNumbersXNumbers); double sumOfBeatNumbers = sum(beatNumbers); // The divisor is: // (n * sum(beatNumbersXNumbers) - (sum(beatNumbers) * sum(beatNumbers))) // Since these are all constants, they can be computed first for better // efficiency. double divisor = (n * sum(beatNumbersXNumbers) - (sum(beatNumbers) * sum(beatNumbers))); // Not enough data to adjust for the first 5 beats for (int i = 0; (i < beatTimes.length) && (i < 5); i++) { adjustedBeatTimes[i] = beatTimes[i]; } // Adjust time for beat i by using timings for beats i-5 through i+5 double[] beatWindow = new double[beatNumbers.length]; for (int i = 0; i < beatTimes.length - 10; i++) { System.arraycopy(beatTimes, i, beatWindow, 0, beatNumbers.length); double[] beatNumbersXTimes = multiplyArrays(beatNumbers, beatWindow); double a = (sum(beatTimes) * sumOfBeatNumbersXNumbers - sumOfBeatNumbers * sum(beatNumbersXTimes)) / divisor; double b = (n * sum(beatNumbersXTimes) - sumOfBeatNumbers * sum(beatTimes)) / divisor; adjustedBeatTimes[i + 5] = a + b * beatNumbers[5]; } if (beatTimes.length - 10 < 0) { return; } // Not enough data to adjust for the last 5 beats for (int i = beatTimes.length - 10; i < beatTimes.length; i++) { adjustedBeatTimes[i] = beatTimes[i]; } } public ArrayList<Target> adjustBeatTargets(ArrayList Other Android examples (source code examples)Here is a short list of links related to this Android BeatTimingsAdjuster.java source code file: |
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