Enter the following code in a new cell in the worksheet to define the spheres using NumPy:
import numpy dimension = 20 num_particles = 500 radius = 1.0 rng = numpy.random.mtrand.RandomState(seed=[1]) x_np = rng.uniform(0, dimension, num_particles) y_np = rng.uniform(0, dimension, num_particles) z_np = rng.uniform(0, dimension, num_particles)
Now, enter the following code in another cell to detect collisions:
%time
collisions_4 = numpy.zeros(num_particles, dtype=numpy.bool)
r_min = numpy.float64(4*radius**2)
for i in range(num_particles):
for j in range(0,i):
r_squared = (x_np[i] - x_np[j])*(x_np[i] - x_np[j]) \
+ (y_np[i] - y_np[j])*(y_np[i] - y_np[j]) \
+ (z_np[i] - z_np[j])*(z_np[i] - z_np[j])
if r_squared < r_min:
collisions_4[i] = True
for j in range(i+1,num_particles):
r_squared = (x_np[i] - x_np[j])*(x_np[i] - x_np[j]) \
+ (y_np[i] - y_np[j])*(y_np[i] - y_np[j]) \
...