Why is this the answer?

[inhouseprodburner]

For the supervised learning course, week 1, in the last programming lab for logistic regression, in the last unit test below, why does the unit test expect 3 values for the weights?

Compute and display cost and gradient with non-zero w and b

test_w = np.array([ 0.2, -0.5])
test_b = -24
dj_db, dj_dw = compute_gradient(X_train, y_train, test_w, test_b)

print(‘dj_db at test w and b:’, dj_db)
print(‘dj_dw at test w and b:’, dj_dw.tolist())

UNIT TESTS

compute_gradient_test(compute_gradient)

[paulinpaloalto]

There are multiple test cases there. The one that is directly visible in the notebook has 2 elements in w, and thus in dw. But there must be a test case in public_tests.py/compute_gradient_test that has 3 elements. So why would your code fail in that case? One possible way would be if you referenced global variables in the body of your compute_gradient function.

You can click “File → Open” and then open the file public_tests.py to see what the additional test cases look like.