express a ( x2-x1) condition in a while loop how?

for my while loop how do i express my condition to be (x2-x1)<0.01?

x=3;
z=0;
while z<0.01
    x=3;
    n=x+1
    i = randfunction(func,a,b,n)
    x=x+2;
end

randfunction is my created function while a and b is my input as for lower and upper limit and n is my number of points between this limits how do i express in a way if my randfunction = 4 when n=3 and when n=4 my randfunction = 5, these two subtract and if their value isn't lesser than 0.01 the loop continue till their subtracted value get a value of <0.01?

Answer 1

[Walter Roberson]

   while true
     x = 3;
     n = x + 1;
     i = randfunction(func,a,b,n);
     x = x + 2;
     if (n - i) < 0.01
       break
     end
   end

I cannot tell whether you would want (n-i)<0.01 or (i-n)<0.01 as your ending condition. If you are trying to determine whether they are within 0.01 of each other, then

   if abs(n-i) < 0.01