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199 lines
6.6 KiB
C++
199 lines
6.6 KiB
C++
//----------------------------------------------------------------------
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// File: ann_sample.cpp
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// Programmer: Sunil Arya and David Mount
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// Last modified: 03/04/98 (Release 0.1)
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// Description: Sample program for ANN
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//----------------------------------------------------------------------
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// Copyright (c) 1997-2005 University of Maryland and Sunil Arya and
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// David Mount. All Rights Reserved.
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//
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// This software and related documentation is part of the Approximate
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// Nearest Neighbor Library (ANN). This software is provided under
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// the provisions of the Lesser GNU Public License (LGPL). See the
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// file ../ReadMe.txt for further information.
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//
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// The University of Maryland (U.M.) and the authors make no
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// representations about the suitability or fitness of this software for
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// any purpose. It is provided "as is" without express or implied
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// warranty.
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//----------------------------------------------------------------------
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#include <cstdlib> // C standard library
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#include <cstdio> // C I/O (for sscanf)
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#include <cstring> // string manipulation
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#include <fstream> // file I/O
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#include <ANN/ANN.h> // ANN declarations
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using namespace std; // make std:: accessible
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//----------------------------------------------------------------------
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// ann_sample
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//
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// This is a simple sample program for the ANN library. After compiling,
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// it can be run as follows.
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//
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// ann_sample [-d dim] [-max mpts] [-nn k] [-e eps] [-df data] [-qf query]
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//
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// where
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// dim is the dimension of the space (default = 2)
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// mpts maximum number of data points (default = 1000)
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// k number of nearest neighbors per query (default 1)
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// eps is the error bound (default = 0.0)
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// data file containing data points
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// query file containing query points
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//
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// Results are sent to the standard output.
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//----------------------------------------------------------------------
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//----------------------------------------------------------------------
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// Parameters that are set in getArgs()
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//----------------------------------------------------------------------
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void getArgs(int argc, char **argv); // get command-line arguments
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int k = 1; // number of nearest neighbors
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int dim = 2; // dimension
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double eps = 0; // error bound
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int maxPts = 1000; // maximum number of data points
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istream* dataIn = NULL; // input for data points
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istream* queryIn = NULL; // input for query points
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bool readPt(istream &in, ANNpoint p) // read point (false on EOF)
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{
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for (int i = 0; i < dim; i++) {
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if(!(in >> p[i])) return false;
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}
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return true;
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}
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void printPt(ostream &out, ANNpoint p) // print point
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{
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out << "(" << p[0];
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for (int i = 1; i < dim; i++) {
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out << ", " << p[i];
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}
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out << ")\n";
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}
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int main(int argc, char **argv)
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{
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int nPts; // actual number of data points
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ANNpointArray dataPts; // data points
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ANNpoint queryPt; // query point
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ANNidxArray nnIdx; // near neighbor indices
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ANNdistArray dists; // near neighbor distances
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ANNkd_tree* kdTree; // search structure
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getArgs(argc, argv); // read command-line arguments
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queryPt = annAllocPt(dim); // allocate query point
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dataPts = annAllocPts(maxPts, dim); // allocate data points
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nnIdx = new ANNidx[k]; // allocate near neigh indices
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dists = new ANNdist[k]; // allocate near neighbor dists
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nPts = 0; // read data points
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cout << "Data Points:\n";
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while (nPts < maxPts && readPt(*dataIn, dataPts[nPts])) {
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printPt(cout, dataPts[nPts]);
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nPts++;
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}
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kdTree = new ANNkd_tree( // build search structure
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dataPts, // the data points
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nPts, // number of points
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dim); // dimension of space
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while (readPt(*queryIn, queryPt)) { // read query points
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cout << "Query point: "; // echo query point
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printPt(cout, queryPt);
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kdTree->annkSearch( // search
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queryPt, // query point
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k, // number of near neighbors
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nnIdx, // nearest neighbors (returned)
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dists, // distance (returned)
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eps); // error bound
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cout << "\tNN:\tIndex\tDistance\n";
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for (int i = 0; i < k; i++) { // print summary
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dists[i] = sqrt(dists[i]); // unsquare distance
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cout << "\t" << i << "\t" << nnIdx[i] << "\t" << dists[i] << "\n";
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}
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}
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delete [] nnIdx; // clean things up
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delete [] dists;
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delete kdTree;
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annClose(); // done with ANN
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return EXIT_SUCCESS;
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}
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//----------------------------------------------------------------------
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// getArgs - get command line arguments
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//----------------------------------------------------------------------
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void getArgs(int argc, char **argv)
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{
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static ifstream dataStream; // data file stream
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static ifstream queryStream; // query file stream
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if (argc <= 1) { // no arguments
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cerr << "Usage:\n\n"
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<< " ann_sample [-d dim] [-max m] [-nn k] [-e eps] [-df data]"
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" [-qf query]\n\n"
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<< " where:\n"
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<< " dim dimension of the space (default = 2)\n"
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<< " m maximum number of data points (default = 1000)\n"
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<< " k number of nearest neighbors per query (default 1)\n"
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<< " eps the error bound (default = 0.0)\n"
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<< " data name of file containing data points\n"
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<< " query name of file containing query points\n\n"
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<< " Results are sent to the standard output.\n"
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<< "\n"
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<< " To run this demo use:\n"
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<< " ann_sample -df data.pts -qf query.pts\n";
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exit(0);
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}
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int i = 1;
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while (i < argc) { // read arguments
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if (!strcmp(argv[i], "-d")) { // -d option
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dim = atoi(argv[++i]); // get dimension to dump
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}
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else if (!strcmp(argv[i], "-max")) { // -max option
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maxPts = atoi(argv[++i]); // get max number of points
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}
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else if (!strcmp(argv[i], "-nn")) { // -nn option
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k = atoi(argv[++i]); // get number of near neighbors
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}
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else if (!strcmp(argv[i], "-e")) { // -e option
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sscanf(argv[++i], "%lf", &eps); // get error bound
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}
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else if (!strcmp(argv[i], "-df")) { // -df option
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dataStream.open(argv[++i], ios::in);// open data file
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if (!dataStream) {
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cerr << "Cannot open data file\n";
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exit(1);
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}
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dataIn = &dataStream; // make this the data stream
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}
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else if (!strcmp(argv[i], "-qf")) { // -qf option
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queryStream.open(argv[++i], ios::in);// open query file
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if (!queryStream) {
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cerr << "Cannot open query file\n";
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exit(1);
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}
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queryIn = &queryStream; // make this query stream
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}
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else { // illegal syntax
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cerr << "Unrecognized option.\n";
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exit(1);
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}
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i++;
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}
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if (dataIn == NULL || queryIn == NULL) {
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cerr << "-df and -qf options must be specified\n";
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exit(1);
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}
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}
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