Subject: Re: CCL:HELP: differential equation

From: [email-masked] (C.S.RAMAN)
Date: Tue, 10 Dec 1996 23:43:02 -0600 (CST)

Jose:

I tried to respond directly, but it bounced back.  Sorry...

> I am here again to ask about *any* way to solve the following
> differential equation
>  dP1/dt    k1 (R10-P1)(k2-k21 P1-k21 P2+k21 R10+k21 R20)
> -------- = ----------------------------------------------
>  dP2/dt    k2 (R20-P2)(k1-k12 P1-k12 P2+k12 R10+k12 R20)
> P1 and P2 are functions of time (t) and also P1=f(P2) and P2=f(P1) [in
> fact, THIS is the point I need to solve!!], whereas k1, k2, k12, k21,
> R10 and R20 are constants.

I would strongly recommend the program EASY-FIT by Prof. Klaus
Schittkowski (Dept. Mathematics Uni. Bayreuth, Germany) to solve your problem.

EASY-FIT is a very powerful interactive software system to identify
parameters in explicit model functions, dynamical systems of equations,
Laplace transforms, ODE etc.  
ODEs are integrated by a couple of explicit and implicit codes, also
with internal numerical differentiation.  Differential algebraic
equations can be solved upto index 3.  

I suggest that you contact Prof. Schittkowski for the program.  His
email address is:  [email-masked]

Cheers
-raman
______________________________________________________________________
C.S.Raman                              Tel: (210) 614-0839
Dept. of Biochemistry                  Fax: (210) 567-2490
University of Texas                    email:[email-masked]
Health Science Center
7703 Floyd Curl Drive                     
San Antonio, TX, 78284-7760  U.S.A.
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     The real problem in speech is not precise language.  
     The problem is clear language. --Richard Feynman
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