Make an while-loop stop when conditions is fullfilled

First of all I am new to MATlab, but I have made this code for Newton's method. My problem is that I have said that the code should make 100 iteration, but I want it to stop when it converges. How can I do this?

Answer 1

[Walter Roberson]

   if convergence_test_goes_here
     break;
   end

for example,

   if abs(fx - prev_fx) < 1E-10
     break
   end

Answer 2

[Weird Rando]

Just use an AND logic '&' to identify both condition for the while loop.

clc
clear

%%Website
%f(x) = x^3 - x + 1 = 0
%f'(x) = 3x^2 - 1
% The root of the function is between -1 and -2

x = -2:0.1:2;
y = x.^3 - x + 1;

plot(x,y)
grid on

%%Example
counter = 0;
converge = -1.3247;
x1 = -1; %initial guess

while counter < 100 & round(x1*10000)/10000 ~= converge 

     x1 =  x1 - (x1^3 - x1 + 1)/(3*x1^2 - 1)
     counter = counter + 1;

end

(source: http://www.ugrad.math.ubc.ca/coursedoc/math100/notes/approx/newton.html)