Histograms of noise functions

noise_histo.py

"""Print out some histograms for the outputs of various noise functions.
The noise function is sampled with a uniformly random set of x/y coordinates in the range [ -100_000, 100_000 ]
"""

from opensimplex import OpenSimplex
import noise
import random, math

buckets = 20
samples = 1000000
char_width = 50


def do(noisefunc):
	histogram = [0] * (buckets)
	for i in range(samples):
		x = random.uniform(-100000, 100000)
		y = random.uniform(-100000, 100000)
		v = noisefunc(x, y)
		p = (v+1) / 2
		b = round(p * (buckets-1))
		histogram[b] += 1

	biggest = max(histogram)
	for i in range(buckets):
		v = histogram[i]
		n = ((i+0.5) / buckets) * 2 - 1
		w = char_width * v / biggest
		c = ''.join(['*'] * round(w))
		print(f'{n: .2f} {c}')


print("Perlin noise")
do(noise.pnoise2)
print("Simplex noise")
do(noise.snoise2)
print("OpenSimplex noise2d")
osn = OpenSimplex()
do(osn.noise2d)

output.txt

Perlin noise
-0.95
-0.85
-0.75
-0.65
-0.55 ***
-0.45 ***********
-0.35 *****************
-0.25 *********************************
-0.15 *******************************************
-0.05 *************************************************
 0.05 **************************************************
 0.15 ********************************************
 0.25 **********************************
 0.35 ****************
 0.45 ***********
 0.55 ***
 0.65 *
 0.75
 0.85
 0.95
 
Simplex noise
-0.95
-0.85 *********
-0.75 **************
-0.65 *************************
-0.55 ************************************************
-0.45 *************************************************
-0.35 **********************************************
-0.25 **********************************************
-0.15 ***********************************************
-0.05 **********************************************
 0.05 ************************************************
 0.15 **************************************************
 0.25 ************************************************
 0.35 ************************************************
 0.45 **************************************************
 0.55 *************************************************
 0.65 ************************
 0.75 **************
 0.85 *********
 0.95
 
OpenSimplex noise2d
-0.95
-0.85
-0.75 *****
-0.65 ***************
-0.55 **************************
-0.45 *****************************************
-0.35 **************************************************
-0.25 **************************************************
-0.15 *************************************************
-0.05 *************************************************
 0.05 **************************************************
 0.15 *************************************************
 0.25 *************************************************
 0.35 *************************************************
 0.45 ****************************************
 0.55 **************************
 0.65 ***************
 0.75 *****
 0.85
 0.95