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comparison CircularCA.py @ 42:039249efe42f

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Chapter 6, exercise 2, #4. Wrote a program to output the center column of a rule 30 CA as a stream of bytes. It is very slow though. It has to run a very long time to produce enough data for dieharder. Committing it now but will have to let it run overnight or something to generate a large file.
author Brian Neal <bgneal@gmail.com>
date Sun, 13 Jan 2013 16:24:00 -0600
parents ae310a2f42b4
children 6cd37534c12e
comparison
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41:d4d9650afe1e 42:039249efe42f
12 12
13 13
14 class CircularCA(CA): 14 class CircularCA(CA):
15 """A circular cellular automaton; the cells are arranged in a ring.""" 15 """A circular cellular automaton; the cells are arranged in a ring."""
16 16
17 def __init__(self, rule, n=100, ratio=2): 17 def __init__(self, rule, n=100, m=50):
18 """Parameters: 18 """Parameters:
19 19
20 * rule: an integer in the range 0-255 that represents the CA rule 20 * rule: an integer in the range 0-255 that represents the CA rule
21 using Wolfram's encoding 21 using Wolfram's encoding
22 * n: the number of rows (time steps) in the result 22 * n: the number of rows (time steps) in the result
23 * ratio: the ratio of columns to rows 23 * m: the number of columns
24 24
25 """ 25 """
26 self.table = self.make_table(rule) 26 self.table = self.make_table(rule)
27 self.n = n 27 self.n = n
28 # a ghost column is added to either end 28 # a ghost column is added to either end
29 self.m = ratio * n + 3 # add 2 ghost columns 29 self.m = m + 2 # add 2 ghost columns
30 self.array = numpy.zeros((n, self.m), dtype=numpy.int8) 30 self.array = numpy.zeros((n, self.m), dtype=numpy.int8)
31 self.next = 0 31 self.next = 0
32 32
33 def start_single(self): 33 def start_single(self):
34 self.array[0, 1] = 1 34 self.array[0, 1] = 1
48 a[i - 1, self.m - 1] = a[i - 1, 1] 48 a[i - 1, self.m - 1] = a[i - 1, 1]
49 49
50 for j in xrange(1, self.m - 1): 50 for j in xrange(1, self.m - 1):
51 a[i, j] = t[tuple(a[i - 1, j-1:j+2])] 51 a[i, j] = t[tuple(a[i - 1, j-1:j+2])]
52 52
53 def loop(self, steps=1):
54 """Executes the given number of time steps."""
55 for i in xrange(steps):
56 self.step()
53 57
54 def get_array(self, start=0, end=None): 58 def get_array(self, start=0, end=None):
55 """Gets a slice of columns from the CA, with slice indices 59 """Gets a slice of columns from the CA, with slice indices
56 (start, end). 60 (start, end).
57 61
60 if end==None: 64 if end==None:
61 return self.array[:, start+1:self.m-1] 65 return self.array[:, start+1:self.m-1]
62 else: 66 else:
63 return self.array[:, start+1:end+1] 67 return self.array[:, start+1:end+1]
64 68
69 def wrap(self):
70 """Copies the last row to row 0, then resets the CA to start back at the
71 top.
72
73 """
74 a = self.array
75 a[0, :] = a[self.next - 1, :]
76 self.next = 1
77
65 78
66 if __name__ == '__main__': 79 if __name__ == '__main__':
67 80
68 import sys 81 import sys
69 from CADrawer import PyplotDrawer 82 from CADrawer import PyplotDrawer
70 83
71 def main(script, rule, n): 84 def main(script, rule, n, m):
72 rule = int(rule) 85 rule = int(rule)
73 n = int(n) 86 n = int(n)
74 ca = CircularCA(rule, n) 87 m = int(m)
88 ca = CircularCA(rule, n, m)
75 ca.start_single() 89 ca.start_single()
76 ca.loop(n - 1) 90 ca.loop(n - 1)
77 91
78 drawer = PyplotDrawer() 92 drawer = PyplotDrawer()
79 drawer.draw(ca) 93 drawer.draw(ca)