E4_10helper.m

function [ ] = E4_10helper( function_file )
%E4_10HELPER Holds common code used in each part.

global nfeval

b = 1;
c = 0;
abserr = 1e-8;
relerr = 1e-6;

nfeval = 0;   %  global variable to count function evaluations.

figure
fplot(function_file, [0 1])
grid on
title(function_file)
xlabel('x');
ylabel('y');

%  Use Zero to find a root.
try
    [b,c,residual,flag] = Zero(function_file,b,c,abserr,relerr);
    
    %  Check flag and print results.
    fprintf('flag = %i \n',flag)
    if     flag ==  0
        fprintf('Computed a root b = %e \n',b);
        fprintf('%i evaluations of f were required. \n',nfeval);
    elseif flag ==  1
        fprintf('Too much work: nfeval = %i \n',nfeval);
        fprintf('There is a root in [b,c] with \n');
        fprintf('b = %e, c = %e \n',b,c);
    elseif flag ==  2
        fprintf('Computed a pole b = %e \n',b);
    end
    fprintf('The residual f(b) = %e \n',residual);
    
catch error
    fprintf('There are no roots in the bracket\n');
end

end