How to oversample an array of n string elements into an array of m string elements

Question

l would like to oversample an array of n element into an array of m elements such that m > n.

For instance let's take n=3

colors=['red','blue','green']

set m =7

What l'm looking for ?

 oversampled_colors=['green','blue','red','red','blue','green','blue']

You should provide any example of you trying this. Anyways, if you just want random oversampling in `oversampled` use `for` loop and set the `range` to your `m` value, then use `randint` from `random` module to randomly pick values from `colors`. — Sqoshu, Feb 28 '18 at 12:59
How it works for strings (in my case) . randint for int values — eric lardon, Feb 28 '18 at 13:01
Your values are stings, but their indexes are ints and those are the things you use. — Sqoshu, Feb 28 '18 at 13:02

score 2 · Accepted Answer · answered Feb 28 '18 at 13:04

2

np.random.choice seems to be what you are looking for

>>> colors=['red','blue','green']
>>> np.random.choice(colors, 7)
array(['red', 'red', 'green', 'red', 'blue', 'red', 'green'], dtype='<U5')

answered Feb 28 '18 at 13:04

Paul Panzer

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`random.choices(colors, k=7)` - `choice` is only one – Patrick Artner Feb 28 '18 at 13:12
1

@PatrickArtner You are probably thinking of the `random` module. `numpy.random` is similar but different. In particular, it is definitely `choice`. `choices` does not exist. – Paul Panzer Feb 28 '18 at 13:15
1

gosh - thanks for pointing that out, you already got the +1 :) consider it +2 now – Patrick Artner Feb 28 '18 at 13:19

Jay Shankar Gupta · Answer 2 · 2018-02-28T13:24:32.340

0

import random
def fun(colors,n,m):
  colors1=[]
  while(len(colors1)<n):
      colors1.append(colors[random.randint(0,m-1)])
  return colors1
colors=['red','blue','green']
oversampled_colors=fun(colors,7,len(colors))
print(oversampled_colors)

edited Feb 28 '18 at 13:24

answered Feb 28 '18 at 13:03

Jay Shankar Gupta

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thank you for your answer. But it's not random. For m = 7 your just in the same order red blue green until you reach 7 colors – eric lardon Feb 28 '18 at 13:06
what about this @ericlardon – Jay Shankar Gupta Feb 28 '18 at 13:24
While this code may answer the question, providing additional context regarding **how** and **why** it solves the problem would improve the answer's long-term value. – Alexander Feb 28 '18 at 15:28

score 0 · Answer 3 · answered May 31 '22 at 15:29

To sample WITH replacement (values can be repeated):

>>> random.choices(['red','blue','green'], k=5)
['green', 'green', 'red', 'blue', 'red']

Also, to sample WITHOUT replacement (values cannot be repeated):

>>> random.sample(['red','blue','green'], k=3)
['blue', 'green', 'red']

How to oversample an array of n string elements into an array of m string elements

3 Answers3