test.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */
 
#include <mrpt/random.h>
#include <mrpt/math/kmeans.h>
#include <mrpt/core/aligned_std_vector.h>
#include <mrpt/system/CTicTac.h>
#include <mrpt/gui/CDisplayWindowPlots.h>
#include <mrpt/math/CArrayNumeric.h>
#include <iostream>
 
using namespace mrpt::math;
using namespace mrpt::gui;
using namespace mrpt::random;
using namespace mrpt::system;
using namespace std;
 
// ------------------------------------------------------
//                              TestKMeans
// ------------------------------------------------------
void TestKMeans()
{
        typedef CArrayDouble<2> CPointType;
        // typedef CArrayFloat<2>  CPointType;
 
        getRandomGenerator().randomize();
        CTicTac tictac;
 
        CDisplayWindowPlots win("k-means results");
 
        cout << "Close the window to end.\n";
 
        while (win.isOpen())
        {
                // Generate N clusters of random points:
                mrpt::aligned_std_vector<CPointType> points;
                const size_t nClusters =
                        2 + (getRandomGenerator().drawUniform32bit() % 4);
 
                for (size_t cl = 0; cl < nClusters; cl++)
                {
                        const size_t nPts = getRandomGenerator().drawUniform(5, 50);
 
                        TPoint2D clCenter;
                        clCenter.x = getRandomGenerator().drawUniform(0, 10);
                        clCenter.y = getRandomGenerator().drawUniform(0, 10);
 
                        for (size_t p = 0; p < nPts; p++)
                        {
                                CPointType v;
                                v[0] = clCenter.x + getRandomGenerator().drawGaussian1D(0, 1);
                                v[1] = clCenter.y + getRandomGenerator().drawGaussian1D(0, 1);
                                points.push_back(v);
                        }
                }
 
                // do k-means
                mrpt::aligned_std_vector<CPointType> centers;
                vector<int> assignments;
                tictac.Tic();
 
                const double cost =
                        mrpt::math::kmeanspp(nClusters, points, assignments, &centers);
 
                cout << "Took: " << tictac.Tac() * 1e3 << " ms.\n";
                cout << "cost: " << cost << endl;
 
                // Show:
                win.clf();
                win.hold_on();
                static const char colors[6] = {'b', 'r', 'k', 'g', 'm', 'c'};
 
                for (size_t c = 0; c < nClusters; c++)
                {
                        CVectorDouble xs, ys;
 
                        for (size_t i = 0; i < points.size(); i++)
                        {
                                if (size_t(assignments[i]) == c)
                                {
                                        xs.push_back(points[i][0]);
                                        ys.push_back(points[i][1]);
                                }
                        }
                        win.plot(xs, ys, mrpt::format(".4%c", colors[c % 6]));
                }
                win.axis_fit();
                win.axis_equal();
 
                cout << "Press any key to generate another random dataset...\n";
                win.waitForKey();
        };
}
 
int main(int argc, char** argv)
{
        try
        {
                TestKMeans();
                return 0;
        }
        catch (std::exception& e)
        {
                std::cout << "MRPT exception caught: " << e.what() << std::endl;
                return -1;
        }
        catch (...)
        {
                printf("Another exception!!");
                return -1;
        }
}