Data Division in MATLAB Neural Network Train Command

While training a neural network in MATLAB I am using "train" command. Is this command auto divide the data into training, testing, and validation sets or we have to divide the data manually.

Answer 1

[Greg Heath]

Consider the example in the fitnet help documentation:

 help fitnet

 [x,t] = simplefit_dataset; net = fitnet(10); 
 net   = train(net,x,t);    view(net)
 y     = net(x);            perf = perform(net,t,y)

 or, better yet, the "greg" version. Notice the absent
 semicolons for automatic printing to sceen

 close all, clear all, clc
 [x,t] = simplefit_dataset;
 [ I N ] = size(x) % [ 1 94 ]
 [ O N ] = size(t) % [ 1 94 ]
 plot(x,t); hold on
 vart1   = var(t,1)  % Reference MSE = 8.3378

 net     = fitnet; % H = 10 default
 % However, the 4 local extrema in the plot suggest
 % that H = 4 is optimal
 rng(0)            % For replication
 [net tr y e ] = train(net,x,t);
 % y = net(x); e = t-y;
 view(net)
 plot( x ,y ,'r--' ) % Recent modification
 NMSE = mse(e)/ vart1 %1.7558e-05
 Rsq  = 1-NMSE        % 1.000

 Now, to answer your question, type in the 
 command window

 >> net.divideFcn

ans =

dividerand

>> net = net % No semicolon

ans = SURPRISE !!!