using Neural Network without toolbox
25 views (last 30 days)
Show older comments
I have to write a code to model Neural Network. I write it with sigmoid function, back propogation, and gradient descent method.
My problem is that I can not insert input higher than 1.
This is my code:
X = (0:0.01:1.5);
X = X';
LX = length(X);
B_size = 1;
NO_B = (LX / B_size);
Y_d = X.^2;
Width = 20;
H = zeros (Width,1);
H_f = zeros (Width,1);
Y = zeros(LX,1);
Y_f = zeros(LX,1);
W1 = rand (Width,B_size);
W2 = rand (B_size,Width);
b1 = 1 ;
b2 = 1 ;
E_total = 1;
Eta = 0.1;
itt = 0;
epoch = 1500;
for e = 1 : epoch
for i = 1 : NO_B
itt = itt + 1;
XX = X( (B_size * (i-1)) +1 : (i*B_size) );
YY_d = Y_d( (B_size * (i-1)) +1 : (i*B_size) );
H = W1*XX + b1;
H_f = SIG(H);
Y = W2*H_f + b2;
Y_f = SIG(Y);
E_total = sum ( 0.5 * (( YY_d - Y_f ).^2)) ;
E(itt) = E_total;
ITT(itt) = itt;
delta = YY_d - Y_f ;
dY = Y_f.*(1-Y_f) ;
dH = H_f.*(1-H_f) ;
pd2 = (delta.*dY) * H_f' ;
pd1 = (XX *((delta.*dY)' * W2).* dH')' ;
W2 = W2 + Eta*pd2;
W1 = W1 + Eta*pd1;
YY_f ( (B_size * (i-1)) +1 : (i*B_size) )= Y_f;
end
end
plot(X,YY_f,'r*',X,Y_d,'b:','LineWidth',2);
function [alpha_f] = SIG(alpha)
%SIGMOID FUNCTION
alpha_f = 1 ./ (1 + ((exp(1)) .^ (-alpha)));
end
2 Comments
Walter Roberson
on 2 Dec 2022
It is not clear to me which is the input that you cannot make larger than 1. Also you did not indicate what happens when you try to do that.
Answers (0)
See Also
Categories
Find more on Sequence and Numeric Feature Data Workflows in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!