The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Software » comp.soft-sys.matlab

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

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

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
hasan batuk

Posts: 4
Registered: 8/13/10
Neural Networks weights and bias help
Posted: Aug 13, 2010 10:47 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hi, i am trying to learn NN toolbox. I tried to creat a networks that multiply the number by 3 and gives as output. For simplicity, i made the transfer function also linear. It works well but i tried to reach the same result by using the bias and weight values.
x -> input
y-> output

a= [ (w1*x + b1) * w2 ]+b2

but it ends up with same as the input value. I am really confused about it. it looks very simple but i couldnt find what i miss. Thanks for your time. the code is below

P=[1:4:200]; % training set
T=P*3; % target set

net.layers{1}.transferFcn = 'purelin'; % making transfer func. as linear


y=sim(net,101) % giving a number say 101 as an input to system and taking 303 as output as expected.

% trying to reach same result by using weight and bias values. it ends up with 101, not 303.

a1=(net.iw{1,1}*101)+net.b{1}; % output of first layer

a2=(net.lw{2,1}*a1)+net.b{2} % output of second layer

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.