Direct sphere.py
From Werner KRAUTH
This page presents the program markov_disks_box.py, a Markov-chain algorithm for four disks in a square box of sides 1.
Contents |
Description
Program
import random
L = [[0.25, 0.25], [0.75, 0.25], [0.25, 0.75], [0.75, 0.75]]
sigma = 0.15
sigma_sq = sigma ** 2
delta = 0.1
n_steps = 1000
for steps in range(n_steps):
a = random.choice(L)
b = [a[0] + random.uniform(-delta, delta), a[1] + random.uniform(-delta, delta)]
min_dist = min((b[0] - c[0]) ** 2 + (b[1] - c[1]) ** 2 for c in L if c != a)
box_cond = min(b[0], b[1]) < sigma or max(b[0], b[1]) > 1.0 - sigma
if not (box_cond or min_dist < 4.0 * sigma ** 2):
a[:] = b
print L
Version
See history for version information.
import random, math
nsamples = 100
for sample in xrange(nsamples):
x, y, z = (random.gauss(0.0, 1.0),
random.gauss(0.0, 1.0),
random.gauss(0.0, 1.0))
length = random.uniform(0.0, 1.0) ** (1.0 / 3.0) \
/ math.sqrt(x ** 2 + y ** 2 + z ** 2)
print x * length, y * length, z * length
