'Latin Hypercube Sampling from a normal distribution (Python)
How to generate 10 random numbers from normal distribution using latin hypercube sampling technique in python 2.7? The range of the random number should be 5 to 14.
I tried following
import random
from random import randint
iter = 10
segSize = 1 / iter
for i in range(iter):
segMin = i * segSize
point = segMin+ (random.normalvariate(7.5,1)*segSize)
pointValue = (point * (14 - 5)) + 4
print point
print pointValue
Thanks
Solution 1:[1]
Try this:
def rand:
import random
from random import randint
iter = 10
segSize = 1/float(iter)
for i in range(iter):
segMin = float(i) * segSize
point = segMin + (random.normalvariate(7.5,1) * segSize)
pointValue = (point * (14 - 5)) + 4
print point
print pointValue
Your issue seems to have been integer multiplication etc, which Python truncates to zero in your division.
When I run it, I get:
0.686848045493
10.1816324094
0.871425699273
11.8428312935
1.08794202088
13.7914781879
1.08502172623
13.7651955361
1.24462345735
15.2016111161
1.10687801576
13.9619021418
1.1394488663
14.2550397967
1.37407532844
16.3666779559
1.54666717385
17.9200045647
1.6465869841
18.8192828569
Solution 2:[2]
Latin Hypercube Sampling (LHS) is supported by the SciPy 1.8.0
(see this link).
To generate a truncated normal sample using LHS:
from scipy.stats import qmc, norm, truncnorm
# Truncated normal sample using Latin Hypercube Sampling
mean, std = 10, 2
dimension, sample_num = 3, 10
clip_a, clip_b = 5, 14
a, b = (clip_a - mean) / std, (clip_b - mean) / std
sample = truncnorm(a, b, loc=mean, scale=std).ppf(lhd)
To generate a normal sample using LHS:
# normal sample using Latin Hypercube Sampling
lhd = qmc.LatinHypercube(d=dimension, optimization="random-cd").random(n=sample_num)
sample = norm(loc=mean, scale=std).ppf(lhd)
Alternatively, you can use pyDOE
to generate LHS sample (see this link).
from pyDOE import lhs
lhd = lhs(dimension, samples=sample_num, criterion="m")
sample = norm(loc=mean, scale=std).ppf(lhd)
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
Solution | Source |
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Solution 1 | learner |
Solution 2 |