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Solving a nonlinear System of equations

2 messages · Andrej Iljitsch Schmelzer, Ravi Varadhan

#
Hello there,

I wish to solve the following nonlinear System of equations:

+ u1 - Vmax11*S1/(S1 + Km11 *(1 + S2/Km21)) - Vmax12*S1/( S1 + Km12 *(1+S2/Km22)) == 0
+ u2 - Vmax22*S2/(S2 + Km22 *(1 + S1/Km12)) - Vmax21*S2/( S2 + Km21 *(1+S1/Km11)) == 0 
+ Vmax11*S1/(S1 + Km11 *(1 + S2/Km21)) + Vmax12*S1/( S1 + Km12 *(1+S2/Km22)) - d1*P1 == 0
+ Vmax22*S2/(S2 + Km22 *(1 + S1/Km12)) + Vmax21*S2/( S2 + Km21 *(1+S1/Km11)) - d2*P2 == 0

S1, S2, P1, P2 are the Variables, 
u1, u2, Vmax11, Vmax12, Vmax21, Vmax22, Km11, Km12, Km21, Km22, d1 and d2 are Parameters which are given before the solving is attempted. My intention/endgame is to vary 2 or more of the Parameters and obtain a heatmap out of the resulting stationary points.



Best Wishes, 

Andrej Schmelzer
#
There are two packages for solving nonlinear systems:  one is the `BBsolve' function in the "BB" package, and the other is `nleqslv' in the "nleqslv" package.


Ravi.  
____________________________________________________________________

Ravi Varadhan, Ph.D.
Assistant Professor,
Division of Geriatric Medicine and Gerontology
School of Medicine
Johns Hopkins University

Ph. (410) 502-2619
email: rvaradhan at jhmi.edu


----- Original Message -----
From: Andrej Iljitsch Schmelzer <andrej-i-schmelzer at gmx.de>
Date: Sunday, October 11, 2009 6:18 pm
Subject: [R] Solving a nonlinear System of equations
To: r-help at r-project.org