function y = dot(a,b)

if length(a) == length(b)
    
    size = length(a);
    if size < 2
        error('The vectors size must greater than one');
    end;
    
else
    error('Vectors size not equal each other');
end;


total= 0;

for i= 1:size
    
    total= total + ( a(i)*b(i) );
    
end;

y = total;