Week 3 Programming assignment: Exercise 6 compute_gradient_reg

Course Q&A Machine Learning Specialization Supervised ML: Regression and Classification
1

Running the test, I’m getting the following assertion error:

dj_db: 0.07138288792343662
First few elements of regularized dj_dw:
[-0.010034426775559609, 0.01047627452123708, 0.055745505756197467, 0.003977852112093805]

AssertionError Traceback (most recent call last)
in
11
12 # UNIT TESTS
—> 13 compute_gradient_reg_test(compute_gradient_reg)

~/work/public_tests.py in compute_gradient_reg_test(target)
123
124 assert np.isclose(dj_db, expected1[0]), f"Wrong dj_db. Expected: {expected1[0]} got: {dj_db}"
→ 125 assert np.allclose(dj_dw, expected1[1]), f"Wrong dj_dw. Expected: {expected1[1]} got: {dj_dw}"
126
127

AssertionError: Wrong dj_dw. Expected: [ 0.19530838 -0.00632206 0.19687367 0.15741161 0.02791437] got: [0.17210345 0.00241732 0.20441898 0.17273973 0.02791437]

My code includes the following lines (as per hint given for this exercise:

Loop over the elements of w

for j in range(n): 
        dj_dw_j_reg = (lambda_ / m) * w[j]

Add the regularization term to the correspoding element of dj_dw

dj_dw[j] = dj_dw[j] + dj_dw_j_reg
    
### END CODE HERE ###         
    
return dj_db, dj_dw

It seems that dj_dw is not updated for each iteration of j. What am I missing. Any suggestions will be much appreciated.

2

Hello @George_Tzotzos

Can you DM your notebook to me and i can take a look.

3

Can you please send me the email address where I should post the notebook.

Many thanks for your help

4

Click on my name → click on message → attach notebook

5

Notebook sent. I hope the correct way. Apologies as I’m not familiar with the interface.

6

No. I have not recieved it @George_Tzotzos

Did you do the following: Click on my name → Click on Message → Upload your notebook → Click on Message

7

I did this but there’s a bug in the system, I think.

I’m uploading the notebook in this mail.

Many thanks

George

8

Hello @George_Tzotzos

In your compute_gradient_reg function, you have not indented the line correctly, where you are adding the regularization term to the corresponding element of dj_dw. As such, the FOR loop is having no effect on that line, while it actually should.

9

Thank you very much. Very grateful to you for pointing out my mistake.

George

10

You are most welcome @George_Tzotzos :blush: Happy Learning!!

11

I have the same problem. I checked my indentation is correct I checked. Can you look at my notebook too. I’m sending you the notebook please check and tell me where I did a mistake.

12

There was no attachment to your email. If you haven’t solved the problem, please resend.

George