# goodwin.ode

#{The Goodwin Oscillator
#Adv. Enz. Reg. 3:425-439
#J. Watrous Summer 08}

#METHOD RK4
#STARTTIME = 0
#STOPTIME=100
#DT = 0.01

param a0=1
param a1=72
param a2=36
param k1=1
param b1=2
param b2=0

 x(0)=2
 y(0)=0

#{these init values will not yield oscillations
#doing parameter plot analysis shows that
#values of x between 0.1 and 3 are best and
#that y values can varry considerably from there}

#mRNA
dx/dt = (a1/(a2 + (k1 * y))) - b1
#protein
dy/dt = a1*x - b2


@ maxstor=40000, total=150, bound=1000

@ total=150,dt=.01,ylo=-5,yhi=5,xlo=0,xhi=150,xp=t,yp=x

done