Why do I receive errors when training a multi-input Series/Parallel NARX network in Neural Network Toolbox 5.0.2 (R2007a)?

I am trying to train a multivariable input using NEWNARXSP.

When I execute the following commands:

a={[0.1] [0.2] [0.3] [0.4] [0.5] [0.6] [0.7] [0.8] [0.9] [1.0]};

b={[-0.1] [0.2] [-0.3] [0.4] [-0.5] [0.6] [-0.7] [0.8] [-0.9] [1.0]};

c={[-0.2] [0.4] [-0.6] [0.8] [-0.2] [0.4] [-0.6] [0.8] [-0.2] [0.4]};

d1=[1 2];

d2=[1 2];

narx_net = newnarxsp({[0.1 1.0],[-0.9 1.0],[-0.6 0.8]},d1,d2,[5 1],{'tansig','purelin'}); 

p=[a;b;c] ;

t=c;

narx_net.trainFcn = 'trainbr';

narx_net.trainParam.show = 10;

narx_net.trainParam.epochs = 600;

narx_net = train(narx_net,p,t);

I receive the following error in TRAIN:

 ??? Error using ==> network.train

 Inputs are incorrect size for network.

 Cell array must have 2 rows.

Answer 1

[MathWorks Support Team]

This change has been incorporated into the documentation in Release 2010b (R2010b). For previous releases, read below for any additional information:

The syntax for the inputs using TRAIN is different using multivariable inputs than for single-input networks.

To work around this issue, please rewrite your code as follows:

a=cell2mat(a);

b=cell2mat(b);

c=cell2mat(c);

d1=[1 2];

d2=[1 2];

narx_net = newnarxsp({[0.1 1.0;-0.9 1.0],[-0.6 0.8]},d1,d2,[5 1],{'tansig','purelin'});

p=[a;b;c];

P=mat2cell(p,[size(p,1)-1  1],ones(size(p,2),1));

T=mat2cell(c,1,ones(size(c,2),1));

narx_net.trainFcn = 'trainbr';

narx_net.trainParam.show = 10;

narx_net.trainParam.epochs = 600;

narx_net=train(narx_net,P,T);