Python Basics with Numpy --Avoid Using Global Variables inside the Function

Course Q&A Deep Learning Specialization Neural Networks and Deep Learning
1

In the Python_Basics_with_Numpy assignment, in Cell #4 on the function for basic sigmoid, I get an error message that says avoid using global variables in the function. However, I did not use any global variables; I only assigned the sigmoid value to “s” and the code passes the test for correctness. How do I avoid the global variables error?

basic_sigmoid(1) = 2.718281828459045
Error: Wrong output.
1 Tests passed
1 Tests failed

AssertionError Traceback (most recent call last)
in
1 print("basic_sigmoid(1) = " + str(basic_sigmoid(1)))
2
----> 3 basic_sigmoid_test(basic_sigmoid)

~/work/release/W2A1/public_tests.py in basic_sigmoid_test(target)
21 ]
22
—> 23 test(test_cases, target)
24
25 def sigmoid_test(target):

~/work/release/W2A1/test_utils.py in test(test_cases, target)
24 print(‘\033[92m’, success," Tests passed")
25 print(‘\033[91m’, len(test_cases) - success, " Tests failed")
—> 26 raise AssertionError(“Not all tests were passed for {}. Check your equations and avoid using global variables inside the function.”.format(target.name))

AssertionError: Not all tests were passed for basic_sigmoid. Check your equations and avoid using global variables inside the function.

2

Hi @Chris_Lewis, check for any close parenthesis that you are missing in the equation. Thanks.

1 Like
3

That is just one possible suggestion of the error. The error is clear from looking at your result for basic_sigmoid(1): the answer you get is just e, right? So you took the instructions a bit too literally: when they said to use math.exp to implement sigmoid, they didn’t just mean that is all you need. math.exp(x) is just e^x. Take another look at the formula for sigmoid, as given in the instructions. It’s a bit more complicated than that, right? :smiley:

The other clue is that the whole point of sigmoid is that it converts the input into something that looks like a probability, meaning that it’s between 0 and 1. So 2.7182… can’t possibly be correct.

5 Likes
4

You are so right! I realized I mistakenly thought the formula was too rudimentary. For those who are encountering the same “global variables” error, I encourage you to go back to the mathematical formula for the sigmoid function and make sure that you implement the entire formula in your code.

3 Likes