trunk/examples/basic/random_points.cc

   1 // Voronoi calculation 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 // Set up constants for the container geometry
  11 const double x_min=-1,x_max=1;
  12 const double y_min=-1,y_max=1;
  13 const double z_min=-1,z_max=1;
  14 const double cvol=(x_max-x_min)*(y_max-y_min)*(z_max-z_min);
  15
  16 // Set up the number of blocks that the container is divided into
  17 const int n_x=6,n_y=6,n_z=6;
  18
  19 // Set the number of particles that are going to be randomly introduced
  20 const int particles=20;
  21
  22 // This function returns a random double between 0 and 1
  23 double rnd() {return double(rand())/RAND_MAX;}
  24
  25 int main() {
  26         int i;
  27         double x,y,z;
  28
  29         // Create a container with the geometry given above, and make it
  30         // non-periodic in each of the three coordinates. Allocate space for
  31         // eight particles within each computational block
  32         container con(x_min,x_max,y_min,y_max,z_min,z_max,n_x,n_y,n_z,
  33                         false,false,false,8);
  34
  35         // Randomly add particles into the container
  36         for(i=0;i<particles;i++) {
  37                 x=x_min+rnd()*(x_max-x_min);
  38                 y=y_min+rnd()*(y_max-y_min);
  39                 z=z_min+rnd()*(z_max-z_min);
  40                 con.put(i,x,y,z);
  41         }
  42
  43         // Sum up the volumes, and check that this matches the container volume
  44         double vvol=con.sum_cell_volumes();
  45         printf("Container volume : %g\n"
  46                "Voronoi volume   : %g\n"
  47                "Difference       : %g\n",cvol,vvol,vvol-cvol);
  48
  49         // Output the particle positions in gnuplot format
  50         con.draw_particles("random_points_p.gnu");
  51
  52         // Output the Voronoi cells in gnuplot format
  53         con.draw_cells_gnuplot("random_points_v.gnu");
  54 }