# parrondo.ode
# this plays the combined game with probability 1/2 each
# Parrondos paradox
game(p,e)=if(ran(1) < (p-e))then(1)else(-1)
par eps=.005,p2=.1,p3=.75,m=3,pa=.5,gamma=.5
# game 1 alone
ca_1'=ca_1+game(pa,eps)
# game 2 alone
pg2p=if(mod(ca_2,m)==0)then(p2)else(p3)
ca_2'=ca_2+game(pg2p,eps)
# game 3
pg2=if(mod(ca_c,m)==0)then(p2)else(p3)
pg1=pa
p=if(ran(1)>gamma)then(pg2)else(pg1)
ca_c'=ca_c+game(p,eps)
@ total=100,meth=discrete,dt=1
done