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Topic: Training multiple data for a single feedforwardnet
Replies: 19   Last Post: Dec 1, 2012 6:14 PM

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 Greg Heath Posts: 6,387 Registered: 12/7/04
Re: Training multiple data for a single feedforwardnet
Posted: Oct 20, 2012 6:41 PM
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"Carlos Aragon" wrote in message <k5n37h\$ier\$1@newscl01ah.mathworks.com>...
> I'm building a feedforwardnet like this:
>
> (..)
> P=[V';ia';w'];
> T=[tq'];
> net=feedforwardnet([5 25],'trainbr');
> (..)
>
> How could i train this neural net for more then one group '[V';ia';w']' ? How is the matlab structure to perform this kind of training?
>
> Note that 'P' in this case is a 10006x3 matrix that i extract from a motor model.

The issue here is that after training with set1, the weights will forget set1
while they are learning set 2. There are a variety of ways to mitigate forgetting.

The best is to use a modication of NEWRB that allows the input of an initial
hidden layer. Then

1. After training with set1, use those weights as initial weights for training with set2 + set1.

2. After training with set1, use those weights as initial weights for training with set2 and a "characteristic subset" of set1. The drawback is how to define that characteristic.

The reason this works is that each hidden node basis function has local region of influence and a 1-to-1 correspondence with a previous worst classified training vector.

Hope this helps.

Greg

Date Subject Author
10/17/12 Carlos Aragon
10/19/12 Greg Heath
10/20/12 Greg Heath
10/29/12 Carlos Aragon
10/31/12 Greg Heath
11/1/12 Carlos Aragon
11/1/12 Greg Heath
11/3/12 Carlos Aragon
11/3/12 Greg Heath
11/5/12 Carlos Aragon
11/16/12 Carlos Aragon
11/17/12 Greg Heath
11/17/12 Carlos Aragon
11/17/12 Greg Heath
11/17/12 Carlos Aragon
11/17/12 Greg Heath
11/18/12 Carlos Aragon
11/18/12 Greg Heath
12/1/12 Carlos Aragon
10/29/12 Carlos Aragon

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