You have a 3D array arr with shape (2, 3, 4). You want to compute the sum over the last two axes to get a 1D array. Which code achieves this?

hard📝 Application Q8 of 15

NumPy - Aggregation Functions

You have a 3D array arr with shape (2, 3, 4). You want to compute the sum over the last two axes to get a 1D array. Which code achieves this?

Anp.sum(arr, axis=(1, 2))

Bnp.sum(arr, axis=0)

Cnp.sum(arr, axis=2)

Dnp.sum(arr, axis=(0, 1))

Step-by-Step Solution

Solution:

Step 1: Understand the array shape and axes
Array shape is (2, 3, 4). Last two axes are 1 and 2.
Step 2: Sum over axes 1 and 2
Using axis=(1, 2) sums over the last two dimensions, resulting in shape (2,).
Final Answer:
np.sum(arr, axis=(1, 2)) produces the desired 1D array -> Option A
Quick Check:
Sum last two axes = axis=(1,2) [OK]

Quick Trick: Use tuple axis to sum multiple axes at once [OK]

Common Mistakes:

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