From BioNetWiki
begin model
#Simple Lotka-Voltera Model for Predator-Prey Relation
begin parameters
#INITIAL CONCENTRATIONS
xnot 40
ynot 40
#KINETIC RATE CONSTANTS
alpha .4
beta .01
gamma .3
cfac .2
delta beta*cfac
end parameters
begin molecule types
#Prey
X()
#Predator
Y()
#Deletion Dummy
Trash()
end molecule types
begin seed species
1 X() xnot
2 Y() ynot
end seed species
begin reaction rules
#Prey reproduces
1 X() -> X() + X() alpha
#Predator reproduces
2 Y() + X() -> Y() + Y() + X() delta
#Predator eats prey
3 X() + Y() -> Y() beta
#Predator dies
4 Y() -> Trash() gamma
end reaction rules
begin observables
1 Molecules Prey X()
2 Molecules Pred Y()
end observables
generate_network({overwrite=>1});
simulate_ode({t_start=>0,t_end=>500,n_steps=>500})
end model
