Issue
Okay, so I found out that you can have arrays with 0s in their shape.
For the case where you have 0 as the only dimension, this makes sense to me. It is an empty array.
np.zeros(0)
But the case where you have something like this:
np.zeros((0, 100))
Is confusing for me. Why is it defined like this?
Solution
As far as I know it’s just a redundant way to express an empty array. It doesn’t seems to matter for python if you have rows of “emptiness”.
Let’s say we have a give array a:
import numpy as np
a = np.zeros((0,100))
If we print a all we get is the empty array itself:
print(a)
>>> []
Moreover we can actually see that despite this a maintain it’s shape”
np.shape(a)
>>> (0, 100)
But if you try to access a given element by position, e.g:
print(a[0])
or
print(a[0][0])
You get an IndexError :
IndexError: index 0 is out of bounds for axis 0 with size 0
Therefore I believe that the mathematical meaning of the empty arrays, despite the shape you assign to them, is the same.
Answered By – Chicrala
Answer Checked By – Pedro (BugsFixing Volunteer)