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how to predict from a trained neural network ?

Asked by farfar on 15 Jan 2018
Latest activity Commented on by Greg Heath
on 15 Feb 2019 at 7:46
Hello I am trying to use neural network to make some prediction based on my input and target data. I have read all related tutorial in Matlab and also looked at the matlab examples. I kinda learned how to develop a network but I dont know how to use this train network to make some prediction ? is there any code that im missing ? does anyone have a sample script that can be shared here?
that's what I have, for example : x=[1 2 3;4 5 3] t=[0.5 0.6 0.7] , net=feedforwardnet(10) , net=train(net,x,t) , perf=perform(net,y,t)
how can I predict the output for a new set of x (xprime=[4 2 3;4 7 8]) based on this trained network? thanks

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2 Answers

Answer by Greg Heath
on 16 Jan 2018
 Accepted Answer

1. Your code should yield an error because you have not defined y.
here are two ways to define output y, error e and normalized mean square error NMSE (= 1-Rsquare)
1. [ net tr ] = train(net,x,t);
y = net(x);
e = t-y;
2. [ net tr y e ] = train(net,x,t); % My favorite
then, in general,
NMSE = mse(e)/mean(var(t',1))
or for 1-dimensional outputs
NMSE = mse(e)/var(t,1)
Hope this helps.
Greg

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Answer by Mritula C on 14 Feb 2019 at 11:15

Hi How do you predicted with a new test class?

  1 Comment

  1. You misplaced your commented question into an Answer Box.
  2. This is a regression prolem. Your question involves classification.
Greg

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