Colleagues,
Let me add that solving nonlinear systems of equations (and many other NLPs) is often a global optimization problem. Hence, the user needs a “sufficiently good” initial solution guess, or should perhaps [also] use global optimization software.
Best wishes,
Janos
Janos D. Pinter, PhD, DSc
Visiting Professor
Department of Industrial Engineering
Ozyegin University
Kusbakisi Cad. No. 2
34662 Altunizade, Uskudar - Istanbul
TURKEY
Tel. +90 216 559 2332
Fax:+90 216 559 2470
janos.pinter@ozyegin.edu.tr
http://www.ozyegin.edu.tr
President
Pinter Consulting Services, Inc., Canada
janos.d.pinter@gmail.com
http://www.pinterconsulting.com
On Wed, Apr 27, 2011 at 9:32 AM, zahra adel wrote:
Hi,
As you know, nonlinear programming is highly dependent on the way it is formulated and on its initial values. I recommmend you read CONOPT manual (CONOPT is normally the default nonlinear solver), especially pages 10-16. You can download the file at www.gams.com/dd/docs/solvers/conopt.pdf
I hope it helps you.
Zahra.
From: saman
To: gamsworld
Sent: Mon, April 25, 2011 9:37:35 PM
Subject: system of nonlinear equation
Hello everybody
I’m beginner in GAMS then I have a question about solving nonlinear
equation system (n equations - n unknowns)
for example I write this code for a simple nonlinear equation solving:
variable fi
equation e1;
e1… 25.51/(5.51-fi)+32.32/(2.32-fi)+1*5/(1-fi)=e=0;
model root /e1/ ;
fi.l=3;
solve root using nlp minimizing fi;
it’s work truly but this code find one root near fi.l=3 and also this
is just one equation!
when I have a system of nonlinear equation with index i for any
variable in equation j, how can I solve it?
yours sincerely!
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