examples/arithmetic.cc

/*
 * @file   arithmetic.cc
 * @author Sebastien Fourey <http://www.greyc.ensicaen.fr/~seb>
 * @date   Tue Aug 21
 * 
 * @brief  Example that shows the usage of the Board library by 
 *         illustating the arithmetic coding principle.
 *         Files arithm.eps, arithm.fig and arithm.svg are created in
 *         the current directory.
 *
 * @copyright 
 */
#include "Board.h"
#include <cstdlib>
#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
using namespace BoardLib;

int main( int argc, char *argv[] )
{
  Board board;
  
  if ( argc == 2 && !strcmp(argv[1],"-h") ) {
    cout << "Usage:   arithmetic [word] \n\n  Where word has letters in {a, b, c, d, e}\n\n";
    exit(0);
  }

  char the_string[1024];
  strcpy( the_string, "cccccccbb" );  
  
  if ( argc == 2 ) { 
    strcpy( the_string, argv[1] );
  }
  
  // char letters[] = "abcde";
  double proba[100] = { 0.2, 0.1, 0.6, 0.05, 0.05 };
  double lefts[100] = { 0, 0.2, 0.3, 0.9, 0.95  };
  Color colors[5] = { Color( 0, 0, 255 ),
                      Color( 0, 255, 0 ),
                      Color( 255, 0, 0 ),
                      Color( 0, 255, 255 ),
                      Color( 255, 255, 0 ) };
    
  char *pc = the_string;
  int h = 0;
  double thickness = 0.5 / strlen( the_string );

  board.drawRectangle( 0, 0, 1.0, 0.5 );

  double left = 0;
  double width = 1.0;
  double w = 1.0;
  double n = 1;
  char str[20];

  board.setLineWidth( 0.5 );
  board.clear( Color( 200, 200, 200 ) );
  while ( *pc ) {
    int i = *pc - 'a';
    left += width * lefts[ i ];
    width *= proba[i];

    board.setPenColorRGBi( 100, 100, 100 ); 
    w /= 2.0;
    n *= 2;
    for ( int k = 0; k < n; k++ )
      board.drawRectangle( k*w, -h * thickness, w, 0.9*thickness );

    board.setPenColor( colors[ i ] );
    board.drawRectangle( left, -h * thickness, width, 0.9*thickness );

    sprintf( str, "%c", *pc );
    board.drawText( (left + width/2.0 ), -(h+0.5) * thickness, str );    
    ++h;
    ++pc;
  }

  // Draw the letters rectangles.
  for ( int k = 0; k < 5; k++ ) {
    board.setPenColor( colors[ k ] );
    board.drawRectangle( lefts[k], thickness, proba[k], 0.9*thickness );      
    sprintf( str, "%c", 'a' + k  );
    board.drawText( lefts[k] + proba[k]/2.0, 0.5*thickness, str );    
  }

  board.save( "arithm.eps" );
  board.save( "arithm.fig" );
  board.save( "arithm.svg" );
  exit(0);
}

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