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// Frustum example code
//
// Author : Chris H. Rycroft (LBL / UC Berkeley)
// Email : chr@alum.mit.edu
// Date : August 30th 2011
#include "voro++.hh"
using namespace voro;
const double pi=3.1415926535897932384626433832795;
int main() {
int i=0;
double x,y,z,evol,vvol;
// Create a container with the geometry given above, and make it
// non-periodic in each of the three coordinates. Allocate space for
// eight particles within each computational block.
container con(-1.2,1.2,-1.2,1.2,0,1,14,14,7,
false,false,false,8);
// Add a cylindrical wall to the container
wall_cone cone(0,0,2,0,0,-1,atan(0.5));
con.add_wall(cone);
// Place particles in a regular grid within the frustum, for points
// which are within the wall boundaries
for(z=0.1;z<1;z+=0.2) for(y=-0.85;y<1;y+=0.2) for(x=-0.95;x<1;x+=0.2) {
if (con.point_inside(x,y,z)) {
con.put(i,x,y,z);i++;
}
}
// Output the particle positions and Voronoi cells in Gnuplot format
con.draw_particles("frustum_p.gnu");
con.draw_cells_gnuplot("frustum_v.gnu");
// Output the particle positions and Voronoi cells in POV-Ray format
con.draw_particles_pov("frustum_p.pov");
con.draw_cells_pov("frustum_v.pov");
// Compute the volume of the Voronoi cells and compare it to the
// exact frustum volume
evol=pi*1*(0.5*0.5+0.5*1+1*1)/3;
vvol=con.sum_cell_volumes();
printf("Exact frustum volume : %g\n"
"Voronoi cell volume : %g\n"
"Difference : %g\n",evol,vvol,vvol-evol);
}
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