how to make a PN code?

I make a PN code for home work. but it's not work but i don't know the reason why. what's the problem n how to build PN code in base on my code. It's my code i know the answer, num_right has to be 60.

var= dec2bin(0:2^9-1)-'0';
var = [ones(512,1),var,ones(512,1)];
num_right = 0;
for k=1 : 512
 if(mod(sum(var(k,:)),2)==1)
  org(1,:)= var(k,:);
   for l=1 :1022
    check(k,l) = org(l,3);
    next_high = rem(sum(org(l,2:11)),2);
    org(l+1,:) = circshift(org(l,:),1);
    org(l+1,1) = next_high;
   end
   check(k,1023) = org(1023,3);
  if(isequal(org(1023,:),var(k,:))==1)
   for m=1:1023
    if(check(k,m)==1)
     check(k,m) = -1;
    end
    if(check(k,m) ==0)
     check(k,m) = 1;
    end
   end
    for n=1:1023
    check_change = circshift(check(k,:),n);
    check_sum(k,n) = sum(check(k,:).*check_change);
   end
   if (check_sum(k,1023) ==1023)
    sum_check = check_sum(k,1:1022).*check_sum(k,1:1022);
    if(sum(check_sum(k,1:1022).*check_sum(k,1:1022))==1022)
    fprintf('%g \n',var(k,:));
    num_right = num_right + 1;
    end
    if(sum(check_sum(k,1:1022).*check_sum(k,1:1022))~=1022)
    continue, end
   if (check_sum(k,1023) ~=1023)  
   continue, end
   end
  end
 end
end
fprintf('%g \n', num_right);

Answer 1

[Dimitris Iliou]

The problem with your code is that the

if(sum(check_sum(k,1:1022).*check_sum(k,1:1022))==1022)

is never true. Due to that, your num_right variable is never modified.

If you debug the code, you will find that the first time you hit that if statement you have the following:

sum(check_sum(k,1:1022).*check_sum(k,1:1022)

ans =

   103968206

and

size(check_sum(k,1:1022).*check_sum(k,1:1022))

ans =

       1        1022

Having said that, I think you might be checking for the wrong thing.

What I would suggest is try debugging your code in order to understand how it works and what you can do to change it.