# asizedis.ode # polymer size distribution # simple polymerization # Mar 4, 2006 # xj= number of fibers of length j # a= conc of monomers # kf, kr = forward and reverse rate constants par kf=10, kr=1, kinit=0.005, adepl=1 a(0)=20 sm99=x100 sm[98..2]=sm[j+1]+x[j+1] #eqn for monomers: # Set adepl=1 for constant total amt, 0 for fixed monomer level a' = adepl*(-kf*a*(sm2-x100+x2)+kr*(sm2+x2)) # initialization from dimers x1'= kinit*a*a+kr*x2-kf*a*x1 x[2..99]'= kf*a*(x[j-1]-x[j])+kr*(x[j+1]-x[j]) x100' = -kr*x100+kf*a*x99 #Computing the total number of fibers Nf=sm2+x2+x1 aux Ntotal=Nf # computing the total and mean length of fibers p1=sum(2,100)of(i'*shift(x2,i'-2))+x1 aux Ltotal=p1 aux Lmean=p1/(Nf+1e-8) @ bounds=10000000, meth=gear, dt=0.05, total=100 done