help-glpk
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## Re: [Help-glpk] var between 2 parameters

 From: Paolo Tofoni Subject: Re: [Help-glpk] var between 2 parameters Date: Thu, 9 Aug 2012 10:55:10 +0200

var check_t1 {(m,k) in FERMI, (j,p,m) in V_TECNOLOGICI } binary;
param BigP :=  max {(j,p) in FERMI} fine_fermo[j,p];

s.t. k2 {(m,k) in FERMI, (j,p,m) in V_TECNOLOGICI}:
inizio_fermo[m,k] <= start[j,p,m] + BigP * check_t1[m,k,j,p];

s.t. k3 {(m,k) in FERMI, (j,p,m) in V_TECNOLOGICI}:
(start[j,p,m] + lt[j,p,m]) - BigP * check_t1[m,k,j,p]<= inizio_fermo[m,k];

where

start[j,p,m],   lt[j,p,m])  are vars and inizio_fermo[m,k] are parmas.

I always obtain all vars set to 0 and the reponse:

OPTIMAL SOLUTION FOUND
Integer optimization begins...
Gomory's cuts enabled
MIR cuts enabled
Cover cuts enabled
Clique cuts enabled
Creating the conflict graph...
The conflict graph has 2*5 vertices and 9 edges
Warning: numerical instability (dual simplex, phase II)
Warning: numerical instability (dual simplex, phase II)
Cuts on level 0: gmi = 1; mir = 36; cov = 2;
Cuts on level 0: mir = 36; cov = 2;
Cuts on level 0: mir = 36; cov = 2;
+   620: mip =     not found yet >=     tree is empty        (0; 1)
PROBLEM HAS NO INTEGER FEASIBLE SOLUTION

but it's not the best solution ... what can I do to solve the issue?