oddeven.m

Mathematical Methods by Moor n Stiling.

% data for odd/even game
% Copyright 1999 by Todd K. Moon

th1=1;  th2=2;
delta1=1;  delta2=2;
L(th1,delta1) = -2;    L(th1,delta2) = 3;
L(th2,delta1) = 3;   L(th2,delta2) = -4;
x1=1;   x2=2;

phi(1,x1) = 1;   phi(1,x2) = 1;
phi(2,x1) = 1;   phi(2,x2) = 2;
phi(3,x1) = 2;   phi(3,x2) = 1;
phi(4,x1) = 2;   phi(4,x2) = 2;

f(th1,x1) = 3/4;   f(th1,x2) = 1-f(th1,x1);
f(th2,x2) = 3/4;   f(th2,x1) = 1-f(th2,x2);
% compute risk
R(th1,1) = L(th1,phi(1,x1))*f(th1,x1) +  L(th1,phi(1,x2))*f(th1,x2);
R(th1,2) = L(th1,phi(2,x1))*f(th1,x1) +  L(th1,phi(2,x2))*f(th1,x2);
R(th1,3) = L(th1,phi(3,x1))*f(th1,x1) +  L(th1,phi(3,x2))*f(th1,x2);
R(th1,4) = L(th1,phi(4,x1))*f(th1,x1) +  L(th1,phi(4,x2))*f(th1,x2);

R(th2,1) = L(th2,phi(1,x1))*f(th2,x1) +  L(th2,phi(1,x2))*f(th2,x2);
R(th2,2) = L(th2,phi(2,x1))*f(th2,x1) +  L(th2,phi(2,x2))*f(th2,x2);
R(th2,3) = L(th2,phi(3,x1))*f(th2,x1) +  L(th2,phi(3,x2))*f(th2,x2);
R(th2,4) = L(th2,phi(4,x1))*f(th2,x1) +  L(th2,phi(4,x2))*f(th2,x2);

subplot(2,2,1)
line([R(1,4),R(1,2),R(1,1),R(1,3),R(1,4)], [R(2,4),R(2,2),R(2,1),R(2,3),R(2,4)])
line([-3 4],[-3 4])
line([0 1],[1 0]);
line([0 4],[0 0])
line([0 0],[0 4])
axis equal

q = 3/13;
y1 = -5/4*q -3/4;
hold on
plot(y1,y1,'o')
p = 21/26;
line([0 p],[0 1-p])
print -dps ../pictures/oddeven.ps
print -deps ../pictures/oddeven.eps

slope = (R(th2,1) - R(th2,2))/(R(th1,1) - R(th1,2))