knnshow.cpp

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/*

Copyright (c) 2010--2011, Stephane Magnenat, ASL, ETHZ, Switzerland
You can contact the author at <stephane at magnenat dot net>

All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the <organization> nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL ETH-ASL BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#include "nabo/nabo.h"
#include <iostream>
#include <fstream>
#include <stdexcept>

using namespace std;
using namespace Nabo;

template<typename T>
typename NearestNeighbourSearch<T>::Matrix load(const char *fileName)
{
        typedef typename NearestNeighbourSearch<T>::Matrix Matrix;
        
        ifstream ifs(fileName);
        if (!ifs.good())
                throw runtime_error(string("Cannot open file ") + fileName);
        
        vector<T> data;
        int dim(0);
        bool firstLine(true);
        
        while (!ifs.eof())
        {
                char line[1024];
                ifs.getline(line, sizeof(line));
                line[sizeof(line)-1] = 0;
                
                char *token = strtok(line, " \t,;");
                while (token)
                {
                        if (firstLine)
                                ++dim;
                        data.push_back(atof(token));
                        //cout << atof(token) << " ";
                        token = strtok(NULL, " \t,;"); // FIXME: non reentrant, use strtok_r
                }
                firstLine = false;
        }
        
        return Matrix::Map(&data[0], dim, data.size() / dim);
}

template<typename T>
void dumpCoordinateForSVG(const typename NearestNeighbourSearch<T>::Vector coord, const float zoom = 1, const float ptSize = 1, const char* style = "stroke=\"black\" fill=\"red\"")
{
        if (coord.size() == 2)
                cout
                        << "<circle cx=\"" << zoom*coord(0)
                        << "\" cy=\"" << zoom*coord(1)
                        << "\" r=\"" << ptSize
                        << "\" stroke-width=\"" << 0.2 * ptSize
                        << "\" " << style << "/>" << endl;
        else
                assert(false);
}

int main(int argc, char* argv[])
{
        typedef Nabo::NearestNeighbourSearch<float>::Matrix Matrix;
        typedef Nabo::NearestNeighbourSearch<float>::Vector Vector;
        typedef Nabo::NearestNeighbourSearch<float>::Index Index;
        typedef Nabo::NearestNeighbourSearch<float>::Indexes Indexes;
        typedef Nabo::BruteForceSearch<float> BFSF;
        typedef Nabo::KDTree<float> KDTF;
        
        if (argc != 2)
        {
                cerr << "Usage " << argv[0] << " DATA" << endl;
                return 1;
        }
        
        Matrix d(load<float>(argv[1]));
        BFSF bfs(d);
        KDTF kdt(d);
        const Index K(10);
        
        // uncomment to compare KDTree with brute force search
        if (K >= d.size())
                return 2;
        const int itCount(100);
        for (int i = 0; i < itCount; ++i)
        {
                //Vector q(bfs.minBound.size());
                //for (int i = 0; i < q.size(); ++i)
                //      q(i) = bfs.minBound(i) + float(rand()) * (bfs.maxBound(i) - bfs.minBound(i)) / float(RAND_MAX);
                Vector q(d.col(rand() % d.cols()));
                q.cwise() += 0.01;
                //cerr << "bfs:\n";
                Indexes indexes_bf(bfs.knn(q, K, false));
                //cerr << "kdt:\n";
                Indexes indexes_kdtree(kdt.knn(q, K, false));
                //cout << indexes_bf.size() << " " << indexes_kdtree.size() << " " << K << endl;
                if (ndexes_bf.size() != indexes_kdtree.size())
                        return 2;
                assert(indexes_bf.size() == indexes_kdtree.size());
                assert(indexes_bf.size() == K);
                //cerr << "\nquery:\n" << q << "\n\n";
                for (size_t j = 0; j < K; ++j)
                {
                        Vector pbf(d.col(indexes_bf[j]));
                        Vector pkdtree(d.col(indexes_kdtree[j]));
                        //cerr << "index " << j << ": " << indexes_bf[j] << ", " << indexes_kdtree[j] << "\n";  
                        //cerr << "point " << j << ": " << "\nbf:\n" << pbf << "\nkdtree:\n" << pkdtree << "\n\n";
                        assert(indexes_bf[j] == indexes_kdtree[j]);
                        assert(dist2(pbf, pkdtree) < numeric_limits<float>::epsilon());
                }
        }
        cerr << "stats kdtree: "
                << kdt.getStatistics().totalVisitCount << " on "
                << itCount * d.cols() << " ("
                << double(100 * kdt.getStatistics().totalVisitCount) /  double(itCount * d.cols()) << " %"
                << ")" << endl;
        
        /*
        // uncomment to randomly get a point and find its minimum
        cout << "<?xml version=\"1.0\" standalone=\"no\"?>" << endl;
        cout << "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">" << endl;
        cout << "<svg width=\"100%\" height=\"100%\" version=\"1.1\" xmlns=\"http://www.w3.org/2000/svg\">" << endl;
        srand(time(0));
        for (int i = 0; i < d.cols(); ++i)
                dumpCoordinateForSVG<float>(d.col(i), 100, 1);
        Vector q(bfs.minBound.size());
        for (int i = 0; i < q.size(); ++i)
                q(i) = bfs.minBound(i) + float(rand()) * (bfs.maxBound(i) - bfs.minBound(i)) / float(RAND_MAX);
        Indexes indexes_bf(bfs.knn(q, K, false));
        for (size_t i = 0; i < K; ++i)
                dumpCoordinateForSVG<float>(d.col(indexes_bf[i]), 100, 1,  "stroke=\"black\" fill=\"green\"");
        dumpCoordinateForSVG<float>(q, 100, 1,  "stroke=\"black\" fill=\"blue\"");
        cout << "</svg>" << endl;
        */
        
        //cout << "Average KDTree visit count: " << double(totKDTreeVisitCount) * 100. / double(itCount * d.cols()) << " %" << endl;
        
        
        return 0;
}