Quote:
Originally Posted by arcticblue
From lecture 9 page 23 of the slides there is an algorithm of how to implement logistic regression. In step 3 it explains how to compute the gradient. Is the Ein value actually a vector or is it a single number? If it's a single number then the weight would be the same for every value in the weight vector so it seems like Ein is a vector. Is my understanding correct?

is a scalar quantity whose value depends on the entire vector of weights
. Step 3 computes the gradient, which is a vector of derivatives of
with respect to each of those weights, so each component of the gradient vector is the derivative with respect to a different weight