To delete elements in your dataset, usenp.delete
Syntax
np.delete(ndarray,elements,axis)
Let's start with this array in x
and delete the 2nd and 4th elements. To do so, we simply need to specify the positions in np.delete
.
Now lets say we have a 2D array. Removing elements will no longer be as easy as removing them from 1D arrays. If you remove just 1 element, the array will have improper dimensions. Hence, all that can be done is to remove entire columns or rows.
Let's start with a new array y
and delete the elements in the 2nd row.
Below, 0 and axis = 1
refers to the elements in the first column. Recall that axis defines whether you choose columns or rows.
y = np.delete(y, 0, axis = 1)
Using the same array, let's try a different combination to delete elements from the second row. Here, 0 and axis = 0
refers to the elements in the first row.
y = np.delete(y, 0, axis = 0)
Remove the elements from the middle column of this array:
myArray = np.matrix([[1, 2, 3], [4, 5, 6], [9, 8, 7]])
Your codes should look like this:
[[1 3] [4 6] [9 7]]