[arcticblue]

As E is a vector I took the error to be the difference between two iterations. So based on that I took the difference of u/u' and v/v' then summed the square of these values and took the square root to get the combined length, taking this to be the error.

I see if I remove the sqrt and just take the error as the sum of the differences squared then I get the correct answer.

Have I just misunderstood how to calculate an error in gradient descent? If I have then if someone could point out the particular slide or section of the lecture to re-watch I would be grateful. Alternatively if this is just something I should have known then a link to something explaining how to calculate the error would be great.

Thank you.