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      1 /*//////////////////////////////////////////////////////////////////////////////////////
      2 // IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
      3 
      4 //  By downloading, copying, installing or using the software you agree to this license.
      5 //  If you do not agree to this license, do not download, install,
      6 //  copy or use the software.
      7 
      8 // This is a implementation of the Logistic Regression algorithm in C++ in OpenCV.
      9 
     10 // AUTHOR:
     11 // Rahul Kavi rahulkavi[at]live[at]com
     12 //
     13 
     14 // contains a subset of data from the popular Iris Dataset (taken from
     15 // "http://archive.ics.uci.edu/ml/datasets/Iris")
     16 
     17 // # You are free to use, change, or redistribute the code in any way you wish for
     18 // # non-commercial purposes, but please maintain the name of the original author.
     19 // # This code comes with no warranty of any kind.
     20 
     21 // #
     22 // # You are free to use, change, or redistribute the code in any way you wish for
     23 // # non-commercial purposes, but please maintain the name of the original author.
     24 // # This code comes with no warranty of any kind.
     25 
     26 // # Logistic Regression ALGORITHM
     27 
     28 //                           License Agreement
     29 //                For Open Source Computer Vision Library
     30 
     31 // Copyright (C) 2000-2008, Intel Corporation, all rights reserved.
     32 // Copyright (C) 2008-2011, Willow Garage Inc., all rights reserved.
     33 // Third party copyrights are property of their respective owners.
     34 
     35 // Redistribution and use in source and binary forms, with or without modification,
     36 // are permitted provided that the following conditions are met:
     37 
     38 //   * Redistributions of source code must retain the above copyright notice,
     39 //     this list of conditions and the following disclaimer.
     40 
     41 //   * Redistributions in binary form must reproduce the above copyright notice,
     42 //     this list of conditions and the following disclaimer in the documentation
     43 //     and/or other materials provided with the distribution.
     44 
     45 //   * The name of the copyright holders may not be used to endorse or promote products
     46 //     derived from this software without specific prior written permission.
     47 
     48 // This software is provided by the copyright holders and contributors "as is" and
     49 // any express or implied warranties, including, but not limited to, the implied
     50 // warranties of merchantability and fitness for a particular purpose are disclaimed.
     51 // In no event shall the Intel Corporation or contributors be liable for any direct,
     52 // indirect, incidental, special, exemplary, or consequential damages
     53 // (including, but not limited to, procurement of substitute goods or services;
     54 // loss of use, data, or profits; or business interruption) however caused
     55 // and on any theory of liability, whether in contract, strict liability,
     56 // or tort (including negligence or otherwise) arising in any way out of
     57 // the use of this software, even if advised of the possibility of such damage.*/
     58 
     59 #include <iostream>
     60 
     61 #include <opencv2/core.hpp>
     62 #include <opencv2/ml.hpp>
     63 #include <opencv2/highgui.hpp>
     64 
     65 using namespace std;
     66 using namespace cv;
     67 using namespace cv::ml;
     68 
     69 static void showImage(const Mat &data, int columns, const String &name)
     70 {
     71     Mat bigImage;
     72     for(int i = 0; i < data.rows; ++i)
     73     {
     74         bigImage.push_back(data.row(i).reshape(0, columns));
     75     }
     76     imshow(name, bigImage.t());
     77 }
     78 
     79 static float calculateAccuracyPercent(const Mat &original, const Mat &predicted)
     80 {
     81     return 100 * (float)countNonZero(original == predicted) / predicted.rows;
     82 }
     83 
     84 int main()
     85 {
     86     const String filename = "../data/data01.xml";
     87     cout << "**********************************************************************" << endl;
     88     cout << filename
     89          << " contains digits 0 and 1 of 20 samples each, collected on an Android device" << endl;
     90     cout << "Each of the collected images are of size 28 x 28 re-arranged to 1 x 784 matrix"
     91          << endl;
     92     cout << "**********************************************************************" << endl;
     93 
     94     Mat data, labels;
     95     {
     96         cout << "loading the dataset...";
     97         FileStorage f;
     98         if(f.open(filename, FileStorage::READ))
     99         {
    100             f["datamat"] >> data;
    101             f["labelsmat"] >> labels;
    102             f.release();
    103         }
    104         else
    105         {
    106             cerr << "file can not be opened: " << filename << endl;
    107             return 1;
    108         }
    109         data.convertTo(data, CV_32F);
    110         labels.convertTo(labels, CV_32F);
    111         cout << "read " << data.rows << " rows of data" << endl;
    112     }
    113 
    114     Mat data_train, data_test;
    115     Mat labels_train, labels_test;
    116     for(int i = 0; i < data.rows; i++)
    117     {
    118         if(i % 2 == 0)
    119         {
    120             data_train.push_back(data.row(i));
    121             labels_train.push_back(labels.row(i));
    122         }
    123         else
    124         {
    125             data_test.push_back(data.row(i));
    126             labels_test.push_back(labels.row(i));
    127         }
    128     }
    129     cout << "training/testing samples count: " << data_train.rows << "/" << data_test.rows << endl;
    130 
    131     // display sample image
    132     showImage(data_train, 28, "train data");
    133     showImage(data_test, 28, "test data");
    134 
    135     // simple case with batch gradient
    136     cout << "training...";
    137     //! [init]
    138     Ptr<LogisticRegression> lr1 = LogisticRegression::create();
    139     lr1->setLearningRate(0.001);
    140     lr1->setIterations(10);
    141     lr1->setRegularization(LogisticRegression::REG_L2);
    142     lr1->setTrainMethod(LogisticRegression::BATCH);
    143     lr1->setMiniBatchSize(1);
    144     //! [init]
    145     lr1->train(data_train, ROW_SAMPLE, labels_train);
    146     cout << "done!" << endl;
    147 
    148     cout << "predicting...";
    149     Mat responses;
    150     lr1->predict(data_test, responses);
    151     cout << "done!" << endl;
    152 
    153     // show prediction report
    154     cout << "original vs predicted:" << endl;
    155     labels_test.convertTo(labels_test, CV_32S);
    156     cout << labels_test.t() << endl;
    157     cout << responses.t() << endl;
    158     cout << "accuracy: " << calculateAccuracyPercent(labels_test, responses) << "%" << endl;
    159 
    160     // save the classfier
    161     const String saveFilename = "NewLR_Trained.xml";
    162     cout << "saving the classifier to " << saveFilename << endl;
    163     lr1->save(saveFilename);
    164 
    165     // load the classifier onto new object
    166     cout << "loading a new classifier from " << saveFilename << endl;
    167     Ptr<LogisticRegression> lr2 = StatModel::load<LogisticRegression>(saveFilename);
    168 
    169     // predict using loaded classifier
    170     cout << "predicting the dataset using the loaded classfier...";
    171     Mat responses2;
    172     lr2->predict(data_test, responses2);
    173     cout << "done!" << endl;
    174 
    175     // calculate accuracy
    176     cout << labels_test.t() << endl;
    177     cout << responses2.t() << endl;
    178     cout << "accuracy: " << calculateAccuracyPercent(labels_test, responses2) << "%" << endl;
    179 
    180     waitKey(0);
    181     return 0;
    182 }
    183