trunk/examples/no_release/split_cell.cc

   1 // Splitting a Voronoi cell example code
   2 //
   3 // Author   : Chris H. Rycroft (LBL / UC Berkeley)
   4 // Email    : chr@alum.mit.edu
   5 // Date     : August 30th 2011
   6
   7 #include "voro++.hh"
   8 using namespace voro;
   9
  10 // This function returns a random floating point number between 0 and 1
  11 double rnd() {return double(rand())/RAND_MAX;}
  12
  13 int main() {
  14         double x,y,z,rsq,r;
  15         voronoicell v,v2;
  16
  17         // Initialize the Voronoi cell to be a cube of side length 2, centered
  18         // on the origin
  19         v.init(-1,1,-1,1,-1,1);
  20
  21         // Cut the cell by 250 random planes which are all a distance 1 away
  22         // from the origin, to make an approximation to a sphere
  23         for(int i=0;i<250;i++) {
  24                 x=2*rnd()-1;
  25                 y=2*rnd()-1;
  26                 z=2*rnd()-1;
  27                 rsq=x*x+y*y+z*z;
  28                 if(rsq>0.01&&rsq<1) {
  29                         r=1/sqrt(rsq);x*=r;y*=r;z*=r;
  30                         v.plane(x,y,z,1);
  31                 }
  32         }
  33
  34         // Make copy of the Voronoi cell
  35         v2=v;
  36
  37         // Cut one copy in one direction, and the other copy in the other direction
  38         v.plane(1,0,0,0);
  39         v2.plane(-1,0,0,0);
  40
  41         // Output the Voronoi cell to a file, in the gnuplot format
  42         v.draw_gnuplot(-0.05,0,0,"split_cell1.gnu");
  43         v2.draw_gnuplot(0.05,0,0,"split_cell2.gnu");
  44 }