True or false output based on a probability
Is there a standard function for Python which outputs True or False probabilistically based开发者_如何学JAVA on the input of a random number from 0 to 1?
example of what I mean:
def decision(probability):
...code goes here...
return ...True or False...
the above example if given an input of, say, 0.7 will return True with a 70% probability and false with a 30% probability
import random
def decision(probability):
return random.random() < probability
Given a function rand
that returns a number between 0 and 1, you can define decision
like this:
bool decision(float probability)
{
return rand()<probability;
}
Assuming that rand() returns a value in the range [0.0, 1.0)
(so can output a 0.0, will never output a 1.0).
Just use PyProbs library. It is very easy to use.
>>> from pyprobs import Probability as pr
>>>
>>> # You can pass float (i.e. 0.5, 0.157), int (i.e. 1, 0) or str (i.e. '50%', '3/11')
>>> pr.prob(50/100)
False
>>> pr.prob(50/100, num=5)
[False, False, False, True, False]
I use this to generate a random boolean in python with a probability:
from random import randint
n=8 # inverse of probability
rand_bool=randint(0,n*n-1)%n==0
so to expand that :
def rand_bool(prob):
s=str(prob)
p=s.index('.')
d=10**(len(s)-p)
return randint(0,d*d-1)%d<int(s[p+1:])
I came up with this myself but it seems to work.
If you want to amass a lot of data, I would suggest using a map:
from numpy import random as rn
p = 0.15
data = rn.random(100)
final_data = list(map(lambda x: x < p, data))
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