CODEWITHSUNDEEP
pythonnumpy
jaehyukchoi49
jaehyukchoi49

Reputation: 151

In Numpy, how to enforce a view to an array remain as a view?

I created a view (x1) to a slice of a NumPy array.

x = np.arange(12).reshape((3,4))
x1 = x[0,:]

If I apply += operator, for example, it modifies the data of the original array x (x1 is the same view to x)

x1 += 10

However, if I apply something more complicated:

x1 = x1**2 + 10

A new array is assigned to x1 and x1 is no longer a view to x, which is not what I want.

I am wondering if there's a Pythonic way to enforce to x1 remain as a view?

Upvotes: 1

Views: 57

Answers (1)

Glauco
Glauco

Reputation: 1463

In these cases, you should use the arr[:] syntax. In this way, you refer to the x1 value. It can be considered as a pointer (kind of).

x1[:] = x1**2 + 10

x1
> array([10, 11, 14, 19])

x
> array([[10, 11, 14, 19],
       [ 4,  5,  6,  7],
       [ 8,  9, 10, 11]])

Upvotes: 3

Related Questions