NARX closed loop network & removedelay: What setting for inputDelays and feedbackDelays?

I'm trying to use a NARX closed loop network to predict y five steps ahead based on x. I'm getting confused in setting inputDelays and feedbackDelays regarding the number of step ahead.

here is my current code

inputDelays = [6:15];

feedbackDelays = [1:10];

hiddenLayerSize = 15;

...

[net,tr] = train(net,inputs,targets,inputStates,layerStates);

...

netc = closeloop(net);

...

netd = removedelay(netc,5);

Question 1: Is this code predicting y(t+5)=f(x(t)) ?

Question 2: If so, what is the difference with using the setting inputDelays = [6:15] and feedbackDelays = [6:15] ?

Many thanks for helping!

Olivier

Answer 1

[Greg Heath]

 net = narxnet(ID,FD)

ID = [ id1, id2,... idmax ]: NONNEGATIVE increasing (not necessarily consecutive) integers

FD = [ fd1, fd2,... fdmax ]: POSITIVE increasing (not necessarily consecutive) integers

If n <= id1 and n < fd1

 netrn = removedelay(net,n);

 IDrn = [ id1-n, id2-n,... idmax-n ]: NONNEGATIVE increasing integers 

 FDrn: [ fd1-n, fd2-n,... fdmax-n ]: POSITIVE increasing integers

=======================================================================

 ID = [ 6:15 ] , FD = [ 1:10 ]

 y(t) = f( x(t-15):x(t-6), y(t-10): y(t-1) );

 removedelay(net,n) subtracts n from each component of both ID and FD PROVIDED

 n < min(FD) and n <= min(ID).

Obviously, n=5 should result in an error.

Hope this helps.

Thank you for formally accepting my answer

Greg