Generate random numbers from a list of numbers

Question

I have a list of numbers:

data = [15, 30, 45]

how to generate a list of N numbers taken randomly from this data list? To get result as:

new_data = [15,15, 30, 45, 15,45, 30, 15, 45, 30, 45, 45, 45, 15, ...]

np.random.randint(15, high=45, size=N) # does not help here

What numpy functions to use for this?

Ideally, yes. In any case numbers should be normally distributed. — dokondr, Jan 29 '20 at 19:09
Why do you want to use NumPy, especially since the example data you've given is in the form of plain Python lists? — AMC, Jan 29 '20 at 19:42
This is a duplicate of: https://stackoverflow.com/q/43506766/11301900, https://stackoverflow.com/q/306400/11301900 — AMC, Jan 29 '20 at 19:42

score 1 · Answer 1 · answered Jan 29 '20 at 19:10

1

numpy.random.choice can do this:

import numpy

data = [15, 30, 45]
N = 20
new_data = numpy.random.choice(data, N)
print(new_data)

https://ideone.com/ECqtJ3

answered Jan 29 '20 at 19:10

Fred Larson

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Celius Stingher · Accepted Answer · 2020-01-29T19:30:00.150

1

You can simply use np.random.choice:

import numpy as np 
data=[15,30,45]
N = 50
new_list = np.random.choice(data,N)

Edit: Using random.sample() won't work as the sampling is done without replacement, therefore samples can't exceed length of the original data.

edited Jan 29 '20 at 19:30

answered Jan 29 '20 at 19:11

Celius Stingher

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Thanks. I've edited the code and forgot to change the import as I used `random` first. – Celius Stingher Jan 29 '20 at 19:30

score 1 · Answer 3 · answered Jan 29 '20 at 19:44

1

For a non-Numpy solution:

import random


l = [15, 30, 45]
N = 30
result = [random.choice(l) for i in range(N)]

# outputs: [15, 30, 15, 45, 15, 15, 30, 15, 30, 45, 15, 45, 30, 15, 30, 15, 15, 45, 30, 45, 30, 45, 45, 15, 15, 45, 30, 45, 45, 45]

answered Jan 29 '20 at 19:44

revliscano

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score 0 · Answer 4 · answered Jan 29 '20 at 19:33

0

import random

data = [15, 30, 45]
new_data = []
N = 14

for i in range (0, N) :
    new_data.append(random.choice(data))

print("Data: ", data)
print("\nNew data :", new_data)

input("\n\nPress Enter to continue...")

https://ideone.com/5iD9U7

answered Jan 29 '20 at 19:33

Anton Vrdoljak

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Yes, or a list comprehension is cleaner: `new_data = [random.choice(data) for _ in range(N)]` – Fred Larson Jan 29 '20 at 19:41
Works like a charm! – Anton Vrdoljak Jan 29 '20 at 19:50

Generate random numbers from a list of numbers

4 Answers4