Perceptron Learning Algorithm

[mbell]

Originally Posted by virginiatraweek@gmail.com

How do you calculate the desired output (dj), as shown on the wikipedia page?

d_j is the same as y_j in our formulation - it's the known output value for x_j

A word of warning to others (although it sounds like everyone else on the forums is already past this point): You do in fact need to include w_0 (with x_i,0 = 1). I spent quite a while wrestling with my non-converging PLA until I realized this was the issue (and then some more time wondering why my P(f(x) != g(x)) values were so weird, until I realized that I'd failed to account for the extra w_0 when computing f(x) using a 2D x instead of the appropriate 3D version...)

I'd interpreted the value of w_0 from the in-class example as a threshold set by the bank for a credit-worthy customer, but now I realize that in fact it's one of the learned parameters, which makes perfect sense in retrospect.