jgk@osc.COM (Joe Keane) (11/29/90)
In article <4916@trantor.harris-atd.com> mlaprade@x102a.ess.harris.com (laprade maria 42641) writes: >In my neural nets class we were assigned to build a BPP net to approximate >the function z = sin(2PIx)sin(2PIy) for >0<=x<=1 and 0<=y<=1. This is a fairly difficult function, basically a sinusoidal version of XOR. It can also be expressed as z = 1/2*(cos(2*pi*(x-y))-cos(2*pi*(x+y))). Hopefully the nets will learn to use the sum and difference. >Weights were to be initialized to random values between +-0.1. I'd say these weights are too small. You need to give the net a large amount of asymmetry to start with, or it will tend to converge to zero.