Leonardo Lopez - 1 year ago 111

Python Question

If I have an array x, and do an

`np.repeat(x,2)`

`>>> x = np.array([1,2,3,4])`

>>> np.repeat(x, 2)

array([1, 1, 2, 2, 3, 3, 4, 4])

How can I do the opposite so that I end up with the original array?

It should also work with a random array y:

`>>> y = np.array([1,7,9,2,2,8,5,3,4])`

How can I delete every other element so that I end up with the following?

`array([7, 2, 8, 3])`

Answer Source

`y[1::2]`

should do the job. Here the second element is chosen by indexing with 1, and then taken at an interval of 2.