I have this code in matlab but it does not work alone. I think I need a script for it.

function x = Newton_method(f,df,x0,Tol, MaxIter )
%
% NEWTON Newton's Method
%   Newton's method for finding successively better approximations to the
%   zeroes of a real-valued function.
%
% Inputs:
%   f - solve f(x)=0
%   df - derivative of f(x)
%   x0 - initial guess
%   Tol - stopping tolerance
%   MaxIter - maximum number of iterations
%
% Output:%   x - a root of f(x)=0
%
nit=0; %number of iterations
disp('step|   x        |      f(x)   ')
disp('----|------------|-------------')
while 1    
    x = x0 - f(x0)/df(x0);    
    nit=nit+1;    
    if nit>MaxIter       
        disp('Maximum number of iterations is reached!')        
        break    
    end    
    if abs(x-x0)<Tol       
        disp('The sequence is convergent!')       
        break   
    end  
    x0=x;   
    fprintf('%3i |%12.8f|%12.8f\n',nit,x,f(x))
end

[Rik]

Why did you edit away your question? Editing away your question is very rude. Someone spent time reading your question, understanding your issue, figuring out the solution, and writing an answer. Now you repay that kindness by ensuring that the next person with a similar question can't benefit from this answer.

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Walter Roberson]

f = @(x) tan(x) - 5*cos(x)

f = function_handle with value:
    @(x)tan(x)-5*cos(x)

df = matlabFunction(diff(sym(f)))

df = function_handle with value:
    @(x)sin(x).*5.0+tan(x).^2+1.0

x0 = -1

x0 = -1

Tol = .0001

Tol = 1.0000e-04

MaxIter = 100

MaxIter = 100

X = Newton_method(f, df, x0, Tol, MaxIter)

step|   x        |      f(x)   
----|------------|-------------
  1 | -6.44732999| -5.09842737
  2 | 17.78565182| -4.22818795
  3 |-15.21185170|  4.93846493
  4 |-10.66898221| -1.34819199
  5 |-10.57569237| -0.20172506
  6 |-10.55663155| -0.00505942
  7 |-10.55612877| -0.00000325
The sequence is convergent!

X = -10.5561

function x = Newton_method(f,df,x0,Tol, MaxIter )
%
% NEWTON Newton's Method
%   Newton's method for finding successively better approximations to the
%   zeroes of a real-valued function.
%
% Inputs:
%   f - solve f(x)=0
%   df - derivative of f(x)
%   x0 - initial guess
%   Tol - stopping tolerance
%   MaxIter - maximum number of iterations
%
% Output:%   x - a root of f(x)=0
%
nit=0; %number of iterations
disp('step|   x        |      f(x)   ')
disp('----|------------|-------------')
while 1    
    x = x0 - f(x0)/df(x0);    
    nit=nit+1;    
    if nit>MaxIter       
        disp('Maximum number of iterations is reached!')        
        break    
    end    
    if abs(x-x0)<Tol       
        disp('The sequence is convergent!')       
        break   
    end  
    x0=x;   
    fprintf('%3i |%12.8f|%12.8f\n',nit,x,f(x))
end
end

Answer 2

[the cyclist]

Works for me. Here is an example

f  = @(x) x.^2 - 1;
df = @(x) 2*x;

Newton_method(f,df,3,1.e-6,500)

step|   x        |      f(x)   
----|------------|-------------
  1 |  1.66666667|  1.77777778
  2 |  1.13333333|  0.28444444
  3 |  1.00784314|  0.01574779
  4 |  1.00003052|  0.00006104
  5 |  1.00000000|  0.00000000
The sequence is convergent!

ans = 1

function x = Newton_method(f,df,x0,Tol, MaxIter )
%
% NEWTON Newton's Method
%   Newton's method for finding successively better approximations to the
%   zeroes of a real-valued function.
%
% Inputs:
%   f - solve f(x)=0
%   df - derivative of f(x)
%   x0 - initial guess
%   Tol - stopping tolerance
%   MaxIter - maximum number of iterations
%
% Output:%   x - a root of f(x)=0
%
nit=0; %number of iterations
disp('step|   x        |      f(x)   ')
disp('----|------------|-------------')
while 1    
    x = x0 - f(x0)/df(x0);    
    nit=nit+1;    
    if nit>MaxIter       
        disp('Maximum number of iterations is reached!')        
        break    
    end    
    if abs(x-x0)<Tol       
        disp('The sequence is convergent!')       
        break   
    end  
    x0=x;   
    fprintf('%3i |%12.8f|%12.8f\n',nit,x,f(x))
end

end