looks so easy but makes big problems!

hi Im an amateur programmer!!!!!!!! take a look at this

        for j=1:b
            if s(i1,j)==s(i2,j)
                v{i1,i2}(1,j)=0;
            end
            if s(i1,j)~=s(i2,j)
                v{i1,i2}(1,j)=1;
            end
            if j==b
                y=sum(v{i1,i2});
            end
            if y==1 && v{i1,i2}(1,j)==1
                w{i3}(h,:)=s(i1,:);
                w{i3}(h,j)=9;
                h=h+1;
             end
          end

when I run it, it has this error: ??? Undefined function or variable 'y' who knows what the problem is????????

Answer 1

[Matt J]

If y isn't created until j==b

            if j==b
                y=sum(v{i1,i2});
            end

then for j<b, this line won't be able to find y

if y==1 && v{i1,i2}(1,j)==1

[omid kim]

how should I fix it?

[Matt J]

define y for j<b