trunk/examples/no_release/sphere.cc

   1 // Sphere example code
   2 //
   3 // Author   : Chris H. Rycroft (Harvard SEAS)
   4 // Email    : chr@alum.mit.edu
   5 // Date     : August 30th 2011
   6
   7 #include "voro++.hh"
   8 using namespace voro;
   9
  10 const double pi=3.1415926535897932384626433832795;
  11
  12 int main() {
  13         int i=0;
  14         double x,y,z,evol,vvol;
  15
  16         // Create a container with the geometry given above, and make it
  17         // non-periodic in each of the three coordinates. Allocate space for
  18         // eight particles within each computational block.
  19         container con(-5,5,-5,5,-5,5,6,6,6,
  20                         false,false,false,8);
  21
  22         // Add a cylindrical wall to the container
  23         wall_sphere sph(0,0,0,4);
  24         con.add_wall(sph);
  25
  26         // Place particles in a regular grid within the frustum, for points
  27         // which are within the wall boundaries
  28         for(z=-4.5;z<5;z+=1) for(y=-4.5;y<5;y+=1) for(x=-4.5;x<5;x+=1) {
  29                 if (con.point_inside(x,y,z)) {
  30                         con.put(i,x,y,z);i++;
  31                 }
  32         }
  33
  34         // Output the particle positions and Voronoi cells in Gnuplot format
  35         con.draw_particles("sphere_p.gnu");
  36         con.draw_cells_gnuplot("sphere_v.gnu");
  37
  38         // Compute the volume of the Voronoi cells and compare it to the
  39         // exact frustum volume
  40         evol=4/3.0*pi*4*4*4;
  41         vvol=con.sum_cell_volumes();
  42         printf("Exact sphere volume : %g\n"
  43                "Voronoi cell volume  : %g\n"
  44                "Difference           : %g\n",evol,vvol,vvol-evol);
  45 }