NDSolve. SolveDelayed->True

*To*: mathgroup at smc.vnet.net*Subject*: [mg57017] NDSolve. SolveDelayed->True*From*: Chris Fernando <ctf20 at sussex.ac.uk>*Date*: Thu, 12 May 2005 02:33:50 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I am simulating a simple cell containing chemicals. I have a set of kinetic equations for each chemical in the cell. However, the cell grows at a certain rate, and this changes the concentration of the chemicals in it. This means I have to scale the concentrations of chemicals at each timestep of the numerical simulation, according to the factor [(S(t)/S(t+1)]^(3/2). When I was using Eular integration in a C program this was easy. I just did it every timestep. But with NDSolve, how can I scale all the equations for substrate concentration appropriately. In general terms, how do I deal with having to scale the r.h.s. of a set of differential equations on the basis of the function above, where S'[t] is also a differential equation that is being solved in that system!!?? Yours Chrisantha