% 
% Written by:
% -- 
% John L. Weatherwax                2006-12-31
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

close all; 

E = 5; 
S  = linspace(E-20,E+20)'; 
PC = max([S-E,zeros(size(S))],[],2);
PP = max([E-S,zeros(size(S))],[],2);

figure; hold on; grid on; 
ch=plot( S, PC, '-g' ); ph=plot( S, PP, '-rx' ); nph=plot( S, -PP, '-ro' ); 
legend( [ch,ph,nph], {'Call: max(0,S-E)', 'Put: max(0,E-S)', '-Put: -max(0,E-S)'} ); 
axis( [ -15 +25 -15 40 ] ); 
xlabel('stock price at expiration'); ylabel('option value'); 
%saveas( gcf, '../../WriteUp/Graphics/prob_5_7_cp_plot', 'epsc' );