How to generate k percentages?-CodePudding

Given k a random integer between 2 and 7. How to generate a list of k positive numbers whose sum is equal to 1?

Examples of possible expected results:

k = 3 -> list = [0.23, 0.57, 0.2]

k = 3 -> list = [0.41, 0.44, 0.15]

K = 2 -> list = [0.95, 0.5]

CodePudding user response：

You can generate k random numbers (for example in the range 0-1), then divide by their sum.

Example with numpy (for efficiency):

k = 3
import numpy as np
a = np.random.random(k)
out = (a/a.sum()).tolist()

pure python:

k = 3
import random
l = [random.random() for _ in range(k)]
s = sum(l)
out = [e/s for e in l]

example: [0.27830153962545046, 0.19826407925979248, 0.523434381114757]

CodePudding user response：

I hope you are well.

you can use this code to do this:

import numpy as np
def softmax(x):
    res = np.exp(x - np.max(x))
    return res / res.sum()
size=5
list=np.random.random(size)
list=softmax(list)

CodePudding user response：

Using a infinite loop which break once get all k numbers. Repeated numbers may occurs.

import random

#random.seed(3) # for testing purposes

k = 5

partition_of_unit = []
while True:
    if len(partition_of_unit) == k-1:
        break
    n = random.random()
    if sum(partition_of_unit)   n < 1:
        partition_of_unit.append(n)
partition_of_unit.append(1-sum(partition_of_unit))

print(partition_of_unit)
#[0.6229016948897019, 0.029005228283614737, 0.11320596465314436, 0.013114189588902203, 0.22177292258463677]
print(sum(partition_of_unit))
#1.0