Hi All, I write my graded function as below and I think that is the right way. But I got the wrong dj_dw value -0 and don’t know why. Is there anybody can help me check? Thanks in advance.
Screen Shot 2022-06-27 at 1.53.31 PM

The Traceback:

Hello @lymmmm

I havent checked further but right off the bat, I see that 2nd line inside your for loop is
dj_dw + dj_dw + err*x[i]. That should be dj_dw =

Thanks! That’s the problem.