CODEWITHSUNDEEP
pythonnumpy
Awitz
Awitz

Reputation: 306

Numpy Array, remove duplicate in column until new value

So I currently have an array that looks like this,

[[1. 2. 1. 0.]
 [3. 4. 1. 0.]
 [6. 5. 0. 1.]
 [8. 7. 0. 1.]
 [3. 5. 1. 0.]
 [2. 9. 1. 0.]]

Where the third column will indicate a 1 if the first column is greater than the second column, and vise versa with column four. I am trying to remove duplicates in columns three and four for only the number one directly below the first one. I basically want it to look like this.

[[1. 2. 1. 0.]
 [3. 4. 0. 0.]
 [6. 5. 0. 1.]
 [8. 7. 0. 0.]
 [3. 5. 1. 0.]
 [2. 9. 0. 0.]]

Below is my current code, how do I make this change?

import numpy as np
arr = np.array((1,2,3,4,6,5,8,7,3,5,2,9))
arr = np.reshape(arr, (-1,2))
arr = np.append(arr,np.zeros([len(arr),1]),1)
arr = np.append(arr,np.zeros([len(arr),1]),1)

arr[:, 2] = np.where(arr[:, 0] > arr[:, 1], arr[:, 2], 1)
arr[:, 3] = np.where(arr[:, 0] < arr[:, 1], arr[:, 3], 1)

Upvotes: 0

Views: 64

Answers (1)

a_guest
a_guest

Reputation: 36289

You can update the columns by using the 'less than' operator:

arr[1:, 2] = arr[:-1, 2] < arr[1:, 2]

And similarly for the fourth column.

Upvotes: 1

Related Questions