1/* 2 * Copyright 2012, The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef LINEAR_REGRESSION_H_ 18 19#define LINEAR_REGRESSION_H_ 20 21#include <sys/types.h> 22#include <media/stagefright/foundation/ABase.h> 23 24namespace android { 25 26// Helper class to fit a line to a set of points minimizing the sum of 27// squared (orthogonal) distances from line to individual points. 28struct LinearRegression { 29 LinearRegression(size_t historySize); 30 ~LinearRegression(); 31 32 void addPoint(float x, float y); 33 34 bool approxLine(float *n1, float *n2, float *b) const; 35 36private: 37 struct Point { 38 float mX, mY; 39 }; 40 41 size_t mHistorySize; 42 size_t mCount; 43 Point *mHistory; 44 45 float mSumX, mSumY; 46 47 DISALLOW_EVIL_CONSTRUCTORS(LinearRegression); 48}; 49 50} // namespace android 51 52#endif // LINEAR_REGRESSION_H_ 53