% Root finding using fixed-point iteration.

 clear;  
 fprintf(' Fixed-Point Iteration Method.\n');
    
 % If conditions for the existence of a fixed point and convergence of
   % a fixed-point iteration are satisfied we can proceed according to
   %the following procedure.
  
   % Input a tolerance for the error "TOL" and a maximum number of
   % iterations "itmax".

%  INITIAL DATA **************

p0=1;
TOL=.0001;
itmax=100;
A=-1;
B=2;

%    GRAPH OF THE FUNCTION************************************

% step=(B-A)/100;
% x1=A:step:B;
% y1=fp(x1);
% plot(x1,y1)
% xlabel('x'); ylabel('f(x)');
% grid on

   disp('        it                                   Cterr                         p                                 fp(p)');

   for it=1:itmax	
				p=fp(p0);
          Coterr=abs(p-p0);
				disp( [it,Coterr, p, fp(p)]);
       if Coterr <TOL,      		
               fprintf('approx. root= %12.8f\n',p), break, end
   			p0=p;       
end
disp('.................................................................................');        
disp('Final Results');
disp('        it                                   Cterr                         p                                 fp(p)');
				disp( [it, Coterr, p, fp(p)]);

% Exact solution

ExValue=fzero('fp', p0);
disp('Exact Value');
disp(ExValue);

% Absolute error

AbsErr=abs(p-ExValue)