# 3. DEMO -  multiplication of the wolves and rabbits
# (Lotka - Volterra equation)

func wolf,rabbit; # number of the wolves and rabbits
const b1,b2; #  constants of multiplication
const d1,d2; #  constants of mortality

# the multiplication of the wolves is proportional to the number of 
# the rabbits and the mortality rate is constant
wolf'=(b1*rabbit-d1)*wolf;

# the mortality of the rabbits is proportional to the number of 
# the wolves and the multiplication rate is constant
rabbit'=(b2-d2*wolf)*rabbit; 

endmodel;

b1=0.01; # constants
d1=10;
b2=10; 
d2=0.01;

rabbit=1200;                 # initial	numbers
wolf=1000; 


rerr(wolf,0.00005);    # error bounds of the solution
rerr(rabbit,0.00005); 

run(0,1,0.1,wolf,rabbit);  # interval of the modelling

print(table,0,1,0.01,wolf,rabbit); #  table

plot(graph,0,1,0.01,wolf=f,rabbit=n); # graph