stopping a function after 30 iterations

I have been working all day on this coding, i can not figure out how to stop it after 30 iterations

function root %finds the root of the equation F0fX(x) using newton-raphson method
clear all;
clc;
x=.8;
x=newton(x);
fprintf('root found at x= %10.8f\n',x);

function [y]=FofX(x)
%nonlinear function
y= x^2+1;
function  [y]=derofF(x)
%derivative of the function
y=2*x;

function [x]=newton(x)
%code for finding with newton-raphson method
TOL=5e-09;
error=10*TOL;
%Top of the loop
iterations=0;
while(error>TOL)
    delta=-FofX(x)/derofF(x);
    x=x+delta;
    iterations=iterations+1;
    %check for the relative error condition:
    %If too big, loop again;if small enough, end.
    error=abs(delta/x);
end
fprintf('after%4.0f iterations\n',iterations)

thanks for any help

[Walter Roberson]

What problems do you observe for the other functions?

[David bondi]

the program just runs and will not stop unless i stop it and it errors in the delta=-FofX(x)/derofF(x) and x=newton(x)

Answer 1

[David bondi]

adding this to the correct line fixed the issue while(error>TOL&& (iteration<=30)

thank you

Answer 2

[Hossein]

Hi, The function that you are using doesn't have any real root. If you change the function to x^2-1 it works perfectly fine.

[David bondi]

Thank you, However the equation i have to use is the x^2-1, the point of the exercise is to stop the program after 30 iterations