Numpy: How to randomly split/select an matrix into n-different matrices

Question

• I have a numpy matrix with shape of (4601, 58).
• I want to split the matrix randomly as per 60%, 20%, 20% split based on number of rows
• This is for Machin

Answer 1

If you want to randomly select rows, you could just use random.sample from the standard Python library:

import random

population = range(4601) # Your number of rows
choice = random.sample(population, k) # k being the number of samples you require

random.sample samples without replacement, so you don't need to worry about repeated rows ending up in choice. Given a numpy array called matrix, you can select the rows by slicing, like this: matrix[choice].

Of, course, k can be equal to the number of total elements in the population, and then choice would contain a random ordering of the indices for your rows. Then you can partition choice as you please, if that's all you need.