Not getting expected cost output

I have written compute_cost function and executed that with following test code.

Compute cost with some initial values for paramaters w, b

initial_w = 2
initial_b = 1

cost = compute_cost(x_train, y_train, initial_w, initial_b)
print(f’Cost at initial w: {cost:.3f}')

Public tests

from public_tests import *
<class ‘numpy.float64’>
Cost at initial w: 0.099

AssertionError Traceback (most recent call last)
9 # Public tests
10 from public_tests import *
—> 11 compute_cost_test(compute_cost)

~/work/ in compute_cost_test(target)
17 initial_b = 1.0
18 cost = target(x, y, initial_w, initial_b)
—> 19 assert cost == 2, f"Case 2: Cost must be 2 but got {cost}"
21 # print(“Using X with shape (5, 1)”)

AssertionError: Case 2: Cost must be 2 but got 0.5

For the same training data and initial w & b , I am getting cost at initial w ‘a wrong value’ . Please help.

Hi @Gouri_Halde
Welcome to the Community!

You can check the hint below also first you want to do a loop over number of training examples(m), second you want to compute the prediction by multiply the weight w with corsponding training examplex[…] , and add the bias term to the result, after that subtract the result with the corsponding real value y[…], and take the square of it by this equation cost =\sum_{i=0}^{m} (prediction - real\ value\ y)^2 , and after the loop, and before return divide the result with (2*m(number of training example))

Best Regards,

I did the same by defining a compute_cost function. But getting the wrong result.

send me the screen from your code in private message

@Gouri_Halde, you do not need to create your own functions.

Your job is just to add the missing code from the provided function templates, where it says to add your code.

yes I added the missing code only. But when test code was run on jupyter , it is giving me error and wrong result. Whereas same code when executed in spyder , I got the exact answer as given Expected Output.

The indentation of the loop isn’t correct(indentation = use tap space), also after the for loop,you want to divide the cost_sum by 2*m before return it

Got the result. corrected indentation.

Thank You for your help. Got the correct answer after adjusting the indentation.

Gouri Halde

@Gouri_Halde I am happy to hear that you solved the problem

Best Regards,