breaking an if loop

In the following script, why doesn't the break in line 24 get executed?

clf
xx = 1:.01:2;
vec = 1:.01:2;
for i=1:101;
  yy(i)= -1*vec(i)+2 ;
end;
plot(xx,yy,'r')
plot(xx,yy);
axis ([0 10 0 2]);
hold on
N = 100;
xo = 1.8; yo = 1.2;
dx = .01; dy = .01;
for i = 1:N
  x(i) = xo - i*dx;
  y(i) = yo - i*dy;
  plot(x(i),y(i))
  for j = 1:N
      if y(i) < yy(j)&& x(i) < xx(j)
          plot (x(i),y(i),'o')
          break
      end
  end
end

Answer 1

[Andrei Bobrov]

t = false;
for i = 1:N
     if t, break; end
     x(i) = xo - i*dx;
     y(i) = yo - i*dy;
     plot(x(i),y(i))
     for j = 1:N
         if y(i) < yy(j)&& x(i) < xx(j)
             t = true;
             plot (x(i),y(i),'o')
             break
         end
     end
end

Answer 2

[Roger Stafford]

Are you sure the 'break' is not executed? You have placed it within the inner for-loop, so when it performs the break it continues to execute the outer loop. Read Mathworks' documentation: "In nested loops, break exits only from the loop in which it occurs. Control passes to the statement that follows the end of that loop." In your case whenever you have an (i,j) pair for which i+j>81 and i-j>19 both become true, then the break should occur with no further j values for that i value. However it goes right on with the next value of i in the outer loop and this break should therefore occur repeatedly for a number of different values of i, once on each i.

Answer 3

[Azzi Abdelmalek]

What made you think that this line is not executed?

[Fred]

Thanks,

It is not executing as I can observe from the results, Also I can remove it with no change in the results.