0 put the colon after max:. ; so it is
a proper lp format file
1 realize that it is poorly posed because
of the 1e10 range of coefficients.
2 believe the UNBOUNDED solution given by
most option configurations.
3 find a solver that is willing to do
exact rational arithmetic. http://members.jcom.home.ne.jp/masashi777/exlp.html
4 solve it by hand via row elimination.
5 Re scale S1, S2 and L2 for convenience
6 try to give the model some freedom to
keep away from critical points at the boundary of feasible/infeasible
In this case the O1 = 1; .
//max: 1 * S1 + 1 * S2 ;
max: 0.5 * S1 + 0.5e-10 * S2 ;
2 * S1 + 2 * L1 + 2 * L2 + -2 * O1 = 0 ;
-2e10 S2 + 2e10 * L1 + 2 * L2 = 2e10 ;
//1 * O1 = 1 ;
L2 > .001 * O1;
O1 < 1e12;
// O1 < 1.01;
William
From: lp_solve
yahoogroups.com [mailto:lp_solveyahoogroups.com] On Behalf Of masoum rajabi
Sent: Saturday, July 12, 2008 2:04
AM
To: lp_solveyahoogroups.com
Subject: [lp_solve] Fw: lpsolve
problem
|
Hi,
lpsolve
fails to solve the following model. but some times it will be solved with
changiing some default parameter's value and some times no.what can I do?
max 1 * S1 + 1 * S2 ;
1 * S1 + 2 * L1 + 1 * L2 + -2 * O1 = 0 ;
-1 * S2 + 20000000000 * L1 + 1 * L2 = 20000000000 ;
1 * O1 = 1 ;
I'm
looking forward for your answer,
thanks
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