Increasing the number of epochs to reach the performance goal

Hello,

I am training the neural network with input vector of 85*650 and target vector of 26*650. Here is the list of parameters that I have used

     net.trainParam.max_fail = 6;
     net.trainParam.min_grad=1e-5;
     net.trainParam.show=10;
     net.trainParam.lr=0.9;
     net.trainParam.epochs=13500;
     net.trainParam.goal=0.001;

Number of hidden nodes=76

As you can see ,I have set the number of epochs to 13500. Is it OK to set the number of epochs to such a large number?. Performance goal is not reaching if the number of epochs is decreased and I am getting a bad classification while testing.

[An Hoang]

I thought your epochs is so big and too much training is actually bad because the network overfits to the training data, and then performs badly against new data that it hasn't never seen it before.

Answer 1

[Greg Heath]

 [ I N ] = size(input) % [ 85 130 ]
 [ O N ] = size(output) % [ 26 130 ]

 Ntrn   = N - 2*round(0.15*N)% 90
 Ntrneq = Ntrn*O        %  2340 training equations

%Nw = (I+1)*H+(H_1)*O % unknown weights

% Ntrneq >> Nw, or equivalently, H << Hub where

 Hub = -1+ceil((Ntrneq-O) / (I+O+1))  % 20

Try to minimize I and H while using as many defaults as possible.

I don't remember ever having to incease the default numepochs.

Greg

[dream]

I have kept on increasing the number of epochs by trail and error method until the performance goal is met. Is that the right way of doing it?

[Greg Heath]

MY APPROACH IS TO VARY NUMBER OF HIDDEN NODES AND TO DESIGN ~ NTRIALS = 10 NETS FOR EACH CANDIDATE VALUE OF H.

I use as many defaults as possible. Rarely have I considered increasing the maximum number of epochs.

[MD Towhid Ur Rahman]

I like the equations you mentioned here, my question is -"Is there an established paper/ referencce/book that is published by any other author or yourself that metions these equations?" Thanks in advance! If yes, the would you mind sharing the resource with me [Please don't attach links, I just need the Title and Author, I can find it myself]

Answer 2

[Greg Heath]

One problem you have is that you are specifying the mse and mingrad goals without considering the scale of the target. I find that reasonable goals are

 MSEgoal = 0.01*mean(var(ttrn',1))
 MinGrad = MSEgoal/ 200