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Topic: neural network constrain?
Replies: 1   Last Post: Jan 24, 2013 11:47 AM

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 Greg Heath Posts: 6,387 Registered: 12/7/04
Re: neural network constrain?
Posted: Jan 24, 2013 11:47 AM

"Apple" wrote in message <kdmcql\$t3v\$1@newscl01ah.mathworks.com>...
> I try to have a time series nn with 2 outputs V1 and V2 and predict the next pair of values. the simplified medel can be explained as (I don't know how to upload the diagram): Current i1 and i3 in parallel, i1 comes into a R and i3 to a non-linear load; then they merge into single point, then split into two: i2 goes to R and i4 goes to non-linear load, then to ground. All current can't be described by equation and need NN is useful.
>
> As we can see, there are two constrains:
> (1) V2>0
> (2) V1>V2
>
> The NN model provide good training, but the outputs have V2<0 and V1<v2 values.
>
> Is it possible to set constrain to this time series NN?

I gather that your training inputs are i1 and 12, your training targets are V1 > V2 > 0 and you wish to predict V1 and V2 for s timesteps ahead.

Try narxnet with 'logsig' outputs for V2 and V1-V2 that are normalized to the
interval [0,1].

Hope this helps.

Greg

It seems to me that
>
> Apple

Date Subject Author
1/22/13 Apple
1/24/13 Greg Heath