JGetSmallestDistance3D.cc File Reference

Example program to find smallest distance between two points. More...

#include <string>
#include <iostream>
#include <fstream>
#include <iomanip>
#include <vector>
#include "TRandom3.h"
#include "JGeometry3D/JVector3D.hh"
#include "JGeometry3D/JGeometry3DToolkit.hh"
#include "Jeep/JPrint.hh"
#include "Jeep/JTimer.hh"
#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"

Go to the source code of this file.

Functions
int	main (int argc, char *argv[])

Detailed Description

Example program to find smallest distance between two points.

Author

mdejong

Definition in file JGetSmallestDistance3D.cc.

Function Documentation

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 25 of file JGetSmallestDistance3D.cc.

{
  using namespace std;

  string  inputFile;
  string  outputFile;
  int     numberOfPoints;
  UInt_t  seed;
  int     debug;

  try {

    JParser<> zap("Example program to find smallest distance between two points.");

    zap['f'] = make_field(inputFile)           = "";
    zap['o'] = make_field(outputFile)          = "";
    zap['n'] = make_field(numberOfPoints)      =  0;
    zap['S'] = make_field(seed)                =  0;
    zap['d'] = make_field(debug)               =  0;

    zap(argc, argv);
  }
  catch(const exception &error) {
    FATAL(error.what() << endl);
  }

  gRandom->SetSeed(seed);

  using namespace JPP;


  vector<JVector3D> buffer;

  typedef vector<JVector3D>::const_iterator const_iterator;


  if (inputFile != "") {

    ifstream in(inputFile.c_str());

    for (double x, y, z; in >> x >> y >> z; ) {
      buffer.push_back(JVector3D(x,y,z));
    }

    in.close();

  } else if (numberOfPoints > 1) {

    NOTICE("Seed: " << gRandom->GetSeed() << endl);

    for (int i = 0; i != numberOfPoints; ++i) {

      buffer.push_back(JVector3D(gRandom->Uniform(-1.0, +1.0),
                                 gRandom->Uniform(-1.0, +1.0),
                                 gRandom->Uniform(-1.0, +1.0)));
    }

    if (outputFile != "") {
      
      ofstream out(outputFile.c_str(), ios::out);

      for (const_iterator i = buffer.begin(); i != buffer.end(); ++i)
        out << setw(7) << i->getX() << ' ' 
            << setw(7) << i->getX() << ' ' 
            << setw(7) << i->getZ() << endl;
      
      out.close();
    }
  }

  if (buffer.size() < 2) {
    FATAL("Not enough points." << endl);
  }

  for (const_iterator i = buffer.begin(); i != buffer.end(); ++i) {
    DEBUG(i->getX() << ' ' << i->getY() << ' ' << i->getZ() << endl);
  }


  {
    JTimer timer("classic");
  
    timer.start();

    double dmin = numeric_limits<double>::max();
    
    for (const_iterator i = buffer.begin(); i != buffer.end(); ++i) {
      for (const_iterator j = i; ++j != buffer.end(); ) {
        
        const double d = i->getDistance(*j);
        
        if (d < dmin) {
          dmin = d;
        }
      }
    }
    
    timer.stop();

    cout << "Minimal distance " << SCIENTIFIC(12,5) << dmin << endl;
    timer.print(cout);
  }


  JTimer timer("O(n log(n))");
  
  timer.start();
  
  const double dmin = getSmallestDistance3D(buffer.begin(), buffer.end());

  timer.stop();

  cout << "Minimal distance " << SCIENTIFIC(12,5) << dmin << endl;
  timer.print(cout);
}