% 
% Written by:
% -- 
% John L. Weatherwax                2006-05-12
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

close all; 

% The amount of product #1 to produce: 
% 
p_1 = linspace( 0, 20000, 100 ); 

% 
% Part (b):
%

figure; 
% Plot the machine hours constraint: 
fh1=plot( p_1, (1/4)*(20000 - 3*p_1), '-r' ); hold on; 
% With a reinvestment strategy: 
fh2=plot( p_1, (1/0.38)*(4000 - 0.3*p_1), '-b' ); hold on; 
% Without a reinvestment strategy: 
%plot( p_1, (1/2)*(4000 - 3*p_1), '-b' ); hold on; 
% Plot contours of constant profit:
P=10*10^3; 
fh3=plot( p_1, (1/3.78)*(P-3.9*p_1), '-g' ); 
xlabel( 'Amount of product #1 to produce' ); 
ylabel( 'Amount of product #2 to produce' ); title( '' ); 
legend( [ fh1 fh2 fh3 ], { 'Machine hours constraint', ...
		           'Production cost constraint', ...
		           'Example isoprofit line' }, ...
	'location',  'northeast' ); 
axis( [ 0 Inf 0 Inf ] ); 
saveas( gcf, 'Graphics/ex_1_14_b.eps', 'psc2' ); 

p_1 = 20000/3; p_2 = 0; 
0.65*6*p_1 + 0.7*5.4*p_2

p_1 = 0; p_2 = 5000;
0.65*6*p_1 + 0.7*5.4*p_2

% 
% Part (c):
% 

% The amount of product #1 to produce: 
% 
p_1 = linspace( 0, 20000, 100 ); 

figure; 
% Plot the machine hours constraint: 
fh1=plot( p_1, (1/4)*(20200 - 3*p_1), '-xr' ); hold on; 
% With a reinvestment strategy: 
fh2=plot( p_1, (1/0.38)*(4000 - 0.3*p_1), '-xb' ); hold on; 
% Without a reinvestment strategy: 
%plot( p_1, (1/2)*(4000 - 3*p_1), '-b' ); hold on; 
% Plot conours of constant profit:
P=10*10^3; 
fh3=plot( p_1, (1/3.78)*(P+400-3.9*p_1), '-xg' ); 
xlabel( 'Amount of product #1 to produce' ); 
ylabel( 'Amount of product #2 to produce' ); title( '' ); 
legend( [ fh1 fh2 fh3 ], { 'Machine hours constraint', ...
		           'Production cost constraint', ...
		           'Example isoprofit line' }, ...
	'location',  'northeast' ); 
axis( [ 0 Inf 0 Inf ] ); 
saveas( gcf, 'Graphics/ex_1_14_c.eps', 'psc2' ); 

p_1 = 20200/3; p_2 = 0; 
0.65*6*p_1 + 0.7*5.4*p_2 - 400 

p_1 = 0; p_2 = 20200/4;
0.65*6*p_1 + 0.7*5.4*p_2 - 400