blob: 518049cbb31e77a4d7d48b33a3786587fc51c2c6 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
from hashlib import blake2s
from math import ceil
from itertools import count, chain
import numpy as np
def joinArgs(*args):
# Stringifies parameters into a slash-separated string for use in hash keys.
# Idempotent and associative.
return "/".join([str(x) for x in args])
MAX_UNIFORM_INT = 2 ** 32 - 1
def uniformInts(*args):
# Single pseudo-random drawing determined by the joined parameters.
# Returns 4 uniformly random uint64.
s = joinArgs(*args)
h = blake2s(s.encode()).hexdigest()
nums = []
for i in range(0, 64, 8):
nums.append(int(h[i:i+8], 16))
return np.array(nums)
def uniformFloats(*args):
# returns an array of 8 floats in the range [0,1]
return uniformInts(*args) / MAX_UNIFORM_INT
def nUniformFloats(n: int, *args):
# returns a fixed number (which may exceed 8) of floats in the range [0,1]
seed = joinArgs(*args)
nBlocks = ceil(n/8)
blocks = [uniformFloats(seed, x) for x in range(nBlocks)]
return np.concatenate(blocks)[0:n]
def iterUniformFloats(*args):
# returns an infinite sequence of floats in the range [0,1]
seed = joinArgs(*args)
blocks = map(lambda x: list(uniformFloats(seed, x)), count(0))
return chain.from_iterable(blocks)
|
