Example1 - Fade2D Benchmark

This example measures the performance of Fade2D on your computer. Additionally it demonstrates how to use the integrated postscript writer.

---

Output

Note

• Make sure you link against the fast release version and not the debug binary.
  
• Points in degenerate position may slow down the computations.
  
• The time consumption is linear (otherwise your machine has not enough memory)

main()

Inserts 1, 10, 20, 50, 100 million random points

#include <Fade_2D.h>
#include <stdio.h>
#include <map>
#include <string>
#include <sstream>
#include <iomanip>
using namespace GEOM_FADE2D;
void diagram(std::map<unsigned,double>& mNumTime);

int main()
{
    std::map<unsigned,double> mMillPointsSeconds;
    mMillPointsSeconds[1];
    mMillPointsSeconds[10];
    mMillPointsSeconds[20];
    mMillPointsSeconds[50];  // mem consumption: 10.5 GB
    // mMillPointsSeconds[100]; // mem consumption: 21 GB, deactivated as a precaution 

    // Benchmark loop
    for(std::map<unsigned,double>::iterator it(mMillPointsSeconds.begin());
        it!=mMillPointsSeconds.end();++it)
    {
        // Generate random points
        std::vector<Point2> vInputPoints;
        unsigned millionPoints(it->first);
        for(unsigned i=0;i<1000000*millionPoints;++i)
        {
            double x=-100+(200.0*rand()/(RAND_MAX+1.0));
            double y=-100+(200.0*rand()/(RAND_MAX+1.0));
            vInputPoints.push_back(Point2(x,y));
        }
        
        // Start timer
        timer("Insert Points"); 
    
        // Triangulate
        Fade_2D dt(millionPoints*1000000);
        dt.enableMultithreading(); // Under Linux multithreading can be enabled
        dt.insert(vInputPoints);
    
        // Stop timer   
        double elapsed=timer("Insert Points"); 
        mMillPointsSeconds[millionPoints]=elapsed;
    }   

    // Draw a diagram
    diagram(mMillPointsSeconds);
    return 0;   
}

Visualization

The diagram(..) function takes the elapsed time and uses the postscript writer of the library to draw a diagram.

void diagram(std::map<unsigned,double>& mMillionTime)
{
        if(mMillionTime.empty()) return;
        Visualizer2 vis("example1.ps");

        // Draw coordinate axes.
        Color cBlue(0,0,1,0.1);
        Color cBlack(0,0,0,0.01);
        vis.addObject(Segment2(Point2(0,0),Point2(100,0)),cBlue);
        vis.addObject(Segment2(Point2(0,0),Point2(0,60)),cBlue);
        vis.addObject(Label(Point2(45,-5),"million points",false),cBlack);
        vis.addObject(Label(Point2(-5,55),"t[s]",false),cBlack);

        vis.addObject(Label(Point2(40,55),"Fade2D on your machine",false),cBlack);

        Color cRed(1,0,0,0.1);
        Point2 lastPoint(0,0);
        for(std::map<unsigned,double>::iterator it(mMillionTime.begin());it!=mMillionTime.end();++it)
        {
                unsigned millionPoints(it->first);
                double seconds(it->second);

                double xPosition=millionPoints*100.0/mMillionTime.rbegin()->first;
                double yPosition=seconds*50.0/mMillionTime.rbegin()->second;

                Point2 currentPoint(xPosition,yPosition);
                vis.addObject(Segment2(lastPoint,currentPoint),cRed);
                vis.addObject(Label(currentPoint,""),cBlue);
                vis.addObject(Label(Point2(xPosition-2,-2)," "+convertToString(millionPoints),false),cBlack);
                vis.addObject(Label(Point2(xPosition,0),""),cBlack);
                vis.addObject(Label(Point2(-6,yPosition)," "+convertToString(seconds)+" s",false),cBlack);
                vis.addObject(Label(Point2(0,yPosition),""),cBlack);
                vis.addObject(Label(currentPoint,""),cBlue);
                lastPoint=currentPoint;
        }
        vis.writeFile();
}