Python/other/linear_congruential_generator.py
2018-10-19 17:14:25 -05:00

35 lines
1.1 KiB
Python

from __future__ import print_function
__author__ = "Tobias Carryer"
from time import time
class LinearCongruentialGenerator(object):
"""
A pseudorandom number generator.
"""
def __init__( self, multiplier, increment, modulo, seed=int(time()) ):
"""
These parameters are saved and used when nextNumber() is called.
modulo is the largest number that can be generated (exclusive). The most
efficent values are powers of 2. 2^32 is a common value.
"""
self.multiplier = multiplier
self.increment = increment
self.modulo = modulo
self.seed = seed
def next_number( self ):
"""
The smallest number that can be generated is zero.
The largest number that can be generated is modulo-1. modulo is set in the constructor.
"""
self.seed = (self.multiplier * self.seed + self.increment) % self.modulo
return self.seed
if __name__ == "__main__":
# Show the LCG in action.
lcg = LinearCongruentialGenerator(1664525, 1013904223, 2<<31)
while True :
print(lcg.next_number())