C1W2_Assignment_Intriguing_Result

AI Discussions
1

Hi there, would appreciate any thoughts/help from someone knowledgeable with the internal logic structure in Python. Any thoughts?

Wrote the following code:
“”
for i in range(m):
f_wb = w*x[i]+b
dj_dw_i = (f_wb-y[i])*x[i]
dj_db_i = f_wb-y[i]
dj_dw+= dj_dw_i
dj_db+= dj_db_i
dj_dw =dj_dw/m
dj_db =dj_db/m

“”
…and got wrong results. Nevertheless, when I took out of the loop the last two command lines (as below), the code executed correctly. Any help/thoughts on why this happened please?

Many thanks.

2

Code as written divides by m each iteration. You probably want to just divide by m once only to get an average. (I assume the lack of indentation is an artifact of pasting the code in here, not what it looks like in your editor)

3

Indeed, lack of indentation is some shortfall from writing here. The original is indented, but apparently not fully accurate to purpose of the code.

Your explanation makes a lot of sense, now I understand much better the logic behind one version vs the other (correct one) of the code.

Many thanks for taking the time to reply.

1 Like
4

https://docs.python.org/3.10/faq/design.html?highlight=indentation#why-does-python-use-indentation-for-grouping-of-statements

https://docs.python.org/3.9/reference/lexical_analysis.html#indentation

You will definitely get different results depending on whether or not the lines with /m are indented, or grouped within the loop. If you’re new to Python (my inference) you might find the links :bulb:

5

Yes, I am new to Python. While the logic of the course so far is easy to grasp, the implementation is something I struggle with.

Many thanks again.