# tysons circadian model
# from  Biophys. J. 1999 77: 2411-2417
# this is the 2-variable model
q=2/(1+sqrt(1+8*keq*pt))
m'=num/(1+(.5*pt*(1-q)/a)^2)-km*m
pt'=nup*m-(kp1*pt*q+kp2*pt)/(jp+pt*(q+.5*r*(1-q)))-kp3*pt
par keq=200,num=1,km=.1,nup=.5,kp1=10,kp2=.03,kp3=0.1
par a=0.1,jp=.05,r=2
@ total=200
@ nmesh=100
@ xp=pt,yp=m,xlo=0,ylo=0,xhi=4,yhi=10
@ meth=qualrk,tol=1e-6
init m=1,pt=3.1
done