If
[ I N ] = size(P)
[ O N ] = size(T)
The number of training equations is
Neq = prod(size(T)) = N*O
For an I-H-O elman net the number of weights to be estimated is
Nw = net.numWeightElements
= (I+1+H)*H+(H+1)*O = H^2 + (I+O+1)*H + O
The following condition is usually sufficient for successful training
Neq = N*O >> Nw
Depending on the complexity of the underlying I/O relationship
Neq/Nw ~ 10 to 30
is a reasonable range to investigate
Therefore, for I-H-O = 15-10-1
N >> H^2 + (I+O+1)*H + O = 100+170+1 = 271
Taking into consideration that H < 10 may be adequate,
Try starting your search with
N = 3000 for H = 1:10 and Ntrials = 10 different weight initializations
Hope this helps.
Greg
