trunk/examples/no_release/r_pts_interface.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         // Use the C++ interface to do custom computations
  44         double cx,cy,cz,vvol=0;
  45         voronoicell c;
  46         c_loop_all cl(con);
  47         if(cl.start()) do if(con.compute_cell(c,cl)) {
  48
  49                 // Get particle position and ID
  50                 cl.pos(x,y,z);i=cl.pid();
  51
  52                 // Calculate centroid
  53                 c.centroid(cx,cy,cz);
  54                 printf("Particle %2d at (% .3f,% .3f,% .3f), centroid at (% .3f,% .3f,% .3f)\n",
  55                        i,x,y,z,x+cx,y+cy,z+cz);
  56
  57                 // Calculate volume and sum it
  58                 vvol+=c.volume();
  59
  60                 // Do other calculations and store the information
  61                 // ...
  62                 // ...
  63                 // ...
  64
  65         } while(cl.inc());
  66
  67         // Print the volume check
  68         printf("\nContainer volume : %g\n"
  69                "Voronoi volume   : %g\n"
  70                "Difference       : %g\n",cvol,vvol,vvol-cvol);
  71
  72         // Output the particle positions in gnuplot format
  73         con.draw_particles("random_points_p.gnu");
  74
  75         // Output the Voronoi cells in gnuplot format
  76         con.draw_cells_gnuplot("random_points_v.gnu");
  77 }