Thread Subject: infinite

%perceptron to emulate AND function
%Madhumitha
x=[0 0 0 1;0 0 1 1;0 1 0 1;0 1 1 1;1 0 0 1;1 0 1 1;1 1 0 1;1 1 1 1];
t=[-1 -1 -1 -1 -1 -1 -1 1];
w=[0 0 0 0];
wnew=[0 0 0 0];
theta=0.2;
alpha=1;
delw=[0 0 0 0];
yt=[0;0;0;0;0;0;0;0];
wc=0;
count=0;
totalwc=1;
while(1)
    totalwc=0;
    for i=1:8
        y=x*w';
        if y>theta
            yt=1;
        elseif y<-theta
            yt(i,1)=-1;
        else
            yt(i,1)=0;
        end
        if yt(i,1)==t(1,i)
            wnew=w;
        else
            wnew=w+alpha*t*x;
        end
            delw=wnew-w;
          totalwc=sum(abs(delw));
            totalwc=totalwc+wc;
            w=wnew;
    end
         
        totalwc
        count=count+1
        
        if (totalwc==0)
        break;
        end
    end
       
Hi everyone,
   I have written the above code to test the working of a single layer perceptron learning algorithm. The totalwc variable is always struck at 12 and it runs into an infinite loop. I am not able to find out where the error is occurring. I think the while loop is causing all the problem. Pls help me regarding this.
Thanx.

I don't know what is going on with your code, but one thing I think you may be doing unintentionally is the following:

        if y>theta
            yt = 1;
        elseif y<-theta
            yt(i,1) = -1;
        else
            yt(i,1) = 0;
        end

since y is a vector, the comparisons in your statement will only pass if ALL of the values of the comparison are true. Is that what you meant to do?

Thank you for the valuable suggestion. I tried what you were saying as well with y(i,1)>theta and this loop is working fine but the while loop is still running into an infinite loop.Pls suggest an alternative.Thanks

"Matt Fig" <spamanon@yahoo.com> wrote in message <he544b$h9d$1@fred.mathworks.com>...
> I don't know what is going on with your code, but one thing I think you may be doing unintentionally is the following:
>
> if y>theta
> yt = 1;
> elseif y<-theta
> yt(i,1) = -1;
> else
> yt(i,1) = 0;
> end
>
> since y is a vector, the comparisons in your statement will only pass if ALL of the values of the comparison are true. Is that what you meant to do?