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Topic: Neural Networks weights and bias help
Replies: 18   Last Post: Jan 22, 2016 9:11 AM

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Vikas

Posts: 7
Registered: 2/6/14
Re: Neural Networks weights and bias help
Posted: Jan 22, 2016 2:20 AM
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"Greg Heath" <heath@alumni.brown.edu> wrote in message <n7se0f$45h$1@newscl01ah.mathworks.com>...
> "Vikas" wrote in message <n7qkqf$6o$1@newscl01ah.mathworks.com>...
> > "Greg Heath" <heath@alumni.brown.edu> wrote in message <n7ookr$kc3$1@newscl01ah.mathworks.com>...
> > > "Vikas" wrote in message <n7oepr$sju$1@newscl01ah.mathworks.com>...
> > > > "Greg Heath" <heath@alumni.brown.edu> wrote in message <kackrs$k0t$1@newscl01ah.mathworks.com>...
> > > > > "Renan" wrote in message <kaa61v$hau$1@newscl01ah.mathworks.com>...
> > > > > > Please, I´m in the same situation. Did you figure it out?
> > > > >
> > > > > What EXACTLY do you want to do?
> > > > >
> > > > > What version of MATLAB do you have?
> > > > >
> > > > > Please post the documentation you get from the command
> > > > >
> > > > > help newff
> > > > >
> > > > > Greg

> > > >
> > > > What's the difference between BTF (Backprop network training function, default = 'trainlm') and BLF (Backprop weight/bias learning function, default = 'learngdm') in the newff help document? Its some what confusing in the document, can you share your knowledge on this please?
> > > >
> > > > NEWFF(P,T,S,TF,BTF,BLF,PF,IPF,OPF,DDF) takes,
> > > > P - RxQ1 matrix of Q1 representative R-element input vectors.
> > > > T - SNxQ2 matrix of Q2 representative SN-element target vectors.
> > > > Si - Sizes of N-1 hidden layers, S1 to S(N-1), default = [].
> > > > (Output layer size SN is determined from T.)
> > > > TFi - Transfer function of ith layer. Default is 'tansig' for
> > > > hidden layers, and 'purelin' for output layer.
> > > > BTF - Backprop network training function, default = 'trainlm'.
> > > > BLF - Backprop weight/bias learning function, default = 'learngdm'.
> > > > PF - Performance function, default = 'mse'.
> > > > IPF - Row cell array of input processing functions.
> > > > Default is {'fixunknowns','removeconstantrows','mapminmax'}.
> > > > OPF - Row cell array of output processing functions.
> > > > Default is {'removeconstantrows','mapminmax'}.
> > > > DDF - Data division function, default = 'dividerand';

> > >
> > > trainlm is the levenberg-marqardt training function
> > >
> > > help trainlm
> > > doc trainlm
> > >
> > > learngdm is a backpropagation learning algorithm that uses gradient descent with momentum
> > >
> > > help learngdm
> > > doc traingdm
> > >
> > > Happy reading!
> > >
> > > Greg

> >
> > Thanks for reply Greg........ I know these algorithms but my question was why both "trainlm" and "learngdm" need to use in NEWFF(P,T,S,TF,BTF,BLF,PF,IPF,OPF,DDF) as BTF and BLF? As far as ANN is concerned the weights and bais is to optimize through any one of the training algorithm like gradient descent or levenberg-marqwartd and many others algorithm, so what the need to use two algorithms trainlm and learngdm (aka, traingdm) at a time. What BLF is doing here? please share your large knowledge and wisdom over Matlab functions.

>
> I am an engineer with a limited knowledge of source code. Some time ago, source code obtained using the command TYPE was relatively easy to understand. I guess MATLAB felt that was detrimental to the survival (or increase) of the profit level that they desired (or aspired).
>
> Now, not so easy. Anyway, in addition to the HELP and DOC COMMANDS,
> try TYPE.
>
> The best bet is to find the oldest versions of the code possible. I found the 2004 source code very helpful. However, I lost that and later versions in a computer crash. Now, my eyes glaze over when I see the source code.
>
> Good Luck,
>
> Greg


Thanks again.......Its nice to know about you and your work experience through your Matlab account profile."Type" is giving somewhat more details... how to suppress the blf in the newff code (if nargin < 5, blf = 'learngdm'; end) ? from this information the question is now on "btf", that what the need of btf here? and how to suppress one of them in the newff function to check which one is doing what?

Thanks
Vikas



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