View Single Post
  #2  
Old 05-04-2013, 11:10 AM
yaser's Avatar
yaser yaser is offline
Caltech
 
Join Date: Aug 2009
Location: Pasadena, California, USA
Posts: 1,478
Default Re: Basic logistic regression question

Quote:
Originally Posted by arcticblue View Post
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 E-in 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 E-in is a vector. Is my understanding correct?
E_{\rm in} is a scalar quantity whose value depends on the entire vector of weights {\bf w}. Step 3 computes the gradient, which is a vector of derivatives of E_{\rm in} with respect to each of those weights, so each component of the gradient vector is the derivative with respect to a different weight
__________________
Where everyone thinks alike, no one thinks very much
Reply With Quote