??? In an assignment A(I) = B, the number of elements in B and I must be the same.

hello,,

i need help becoz something's wrong with my code,,

please help me,,

that error show that -->>

???  In an assignment  A(I) = B, the number of elements in B and I must be the same. 

Error in ==> w1(i)=w1(i)+dw1(i);

please help me,,

this is my homework and i must collect it tomorrow,,

my Code

p1=[0 1 0 2];

p2=[0 1 0 2];

t=[1 1 1 0];

%Weight

w1=0;

w2=0;

b=1;

teta=0;

w1new=1;

%Iteration

for j=1:3

for i=1:5

%Calculate n 

      n(i)=w1*p1(i)+w2*p2(i)+b;

%Calculate Output

   if n(i)>teta

     a(i)=1;

   else 

     a(i)=0;

end

   %calculate error value

   error(i)= t(i) - a(i);

   dw1(i)=error(i)*p1(i);

   dw2(i)=error(i)*p2(i);

   db{i}=error(i);

   w1(i)=w1(i)+dw1(i);

   w2(i)=w2(i)+dw2(i);

   b(i)=b(i)+db{i};

end

end

disp(['P1 : ',num2str(p1)]);

i dont know what's wrong with my code,,,

please help me :(

[Daniel Shub]

That is not the error I get

??? Attempted to access w1(2); index out of bounds because numel(w1)=1.

[Thomas]

Daniel is correct.. The error is that w1(2) cannot be accessed because you have only put w1=0 (i.e. only one element and you are trying to access it as an array..

[Daniel Shub]

Over writing MATLAB functions with variables (e.g., i, j, error, and db) is bad style and can lead to all sort of problems.

[Greg Heath]

Why are you using loops when your result can be obtained by matrix operations?

Answer 1

[Image Analyst]

I have no idea what this does, or if my "fix" below is what you want, but at least it runs. You didn't initialize p1 and p2 to have the required 5 elements, and you didn't use w1 and w2 as matrices everywhere.

p1=[0 1 0 2 0];
p2=[0 1 0 2 0];
t=[1 1 1 0 0];
%Weight
w1 = zeros(1,5);
w2= zeros(1,5);
b= ones(1, 5);
teta=0;
w1new=1;
%Iteration
for j=1:3
  for i=1:5
    %Calculate n
    n(i)=w1(i)*p1(i)+w2(i)*p2(i)+b(i);
    %Calculate Output
    if n(i)>teta
      a(i)=1;
    else
      a(i)=0;
    end
    %calculate error value
    error(i)= t(i) - a(i);
    dw1(i)=error(i)*p1(i);
    dw2(i)=error(i)*p2(i);
    db{i}=error(i);
    w1(i)=w1(i)+dw1(i);
    w2(i)=w2(i)+dw2(i);
    b(i)=b(i)+db{i};
  end
end

disp(['P1 : ',num2str(p1)]);