flann_mpi_client.cpp

Go to the documentation of this file.

#include <stdio.h>
#include <time.h>
 
#include <cstdlib>
#include <iostream>
#include <FLANN/util/params.h>
#include <FLANN/io/hdf5.h>
#include <FLANN/mpi/client.h>
 
 
 
#define IF_RANK0 if (world.rank()==0)
 
timeval start_time_;
void start_timer(const std::string& message = "")
{
    if (!message.empty()) {
        printf("%s", message.c_str());
        fflush(stdout);
    }
    gettimeofday(&start_time_,NULL);
}
 
double stop_timer()
{
    timeval end_time;
    gettimeofday(&end_time,NULL);
 
    return double(end_time.tv_sec-start_time_.tv_sec)+ double(end_time.tv_usec-start_time_.tv_usec)/1000000;
}
 
float compute_precision(const flann::Matrix<int>& match, const flann::Matrix<int>& indices)
{
    int count = 0;
 
    assert(match.rows == indices.rows);
    size_t nn = std::min(match.cols, indices.cols);
 
    for(size_t i=0; i<match.rows; ++i) {
        for (size_t j=0;j<nn;++j) {
            for (size_t k=0;k<nn;++k) {
                if (match[i][j]==indices[i][k]) {
                    count ++;
                }
            }
        }
    }
 
    return float(count)/(nn*match.rows);
}
 
 
int main(int argc, char* argv[])
{
    try {
 
        flann::Matrix<float> query;
        flann::Matrix<int> match;
 
        flann::load_from_file(query, "sift100K.h5","query");
        flann::load_from_file(match, "sift100K.h5","match");
        //  flann::load_from_file(gt_dists, "sift100K.h5","dists");
 
        flann::mpi::Client index("localhost","9999");
 
        int nn = 1;
        flann::Matrix<int> indices(new int[query.rows*nn], query.rows, nn);
        flann::Matrix<float> dists(new float[query.rows*nn], query.rows, nn);
 
        start_timer("Performing search...\n");
        index.knnSearch(query, indices, dists, nn, flann::SearchParams(64));
        printf("Search done (%g seconds)\n", stop_timer());
 
        printf("Checking results\n");
        float precision = compute_precision(match, indices);
        printf("Precision is: %g\n", precision);
 
    }
    catch (std::exception& e) {
        std::cerr << "Exception: " << e.what() << "\n";
    }
 
    return 0;
}