question about binary variables in MINLP problem

GAMS
1

Hi all,

I am using GAMS to solve a MINLP problem. I define y1, y2 and y3 as binary variables. However, the values for those variables that I obtain are not zero or one. GAMS generates some number between zero and one, like 0.54, 0.216 etc. I am wondering if anyone can help me resolve this problem.

Thank you very much.

Binary Variables
y1(i,j,k) y’s are 0-1 variables (heat exchanegrs)
y2(i,l) y’s are 0-1 variables (hot utility)
y3(j,l) y’s are 0-1 variables (cold utility)

.


result



---- 203 VARIABLE y1.L y’s are 0-1 variables (heat exchanegrs)

1 2

H1.C1 0.547 0.216
H1.C2 0.252 0.239
H2.C1 0.240
H2.C2 0.287 0.287

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2

Hello,

this is because your model is infeasible or in the solve statement you have stated instead of:

Solve “your model” min/max z using MINLP<-RMINLP (which is the relaxed MINLP).

Hope that helps,

Kostas

Τη Τετάρτη, 24 Σεπτεμβρίου 2014 11:12:01 μ.μ. UTC+3, ο χρήστης Calder Cui έγραψε:

Hi all,

I am using GAMS to solve a MINLP problem. I define y1, y2 and y3 as binary variables. However, the values for those variables that I obtain are not zero or one. GAMS generates some number between zero and one, like 0.54, 0.216 etc. I am wondering if anyone can help me resolve this problem.

Thank you very much.

Binary Variables
y1(i,j,k) y’s are 0-1 variables (heat exchanegrs)
y2(i,l) y’s are 0-1 variables (hot utility)
y3(j,l) y’s are 0-1 variables (cold utility)

.


result



---- 203 VARIABLE y1.L y’s are 0-1 variables (heat exchanegrs)

1 2

H1.C1 0.547 0.216
H1.C2 0.252 0.239
H2.C1 0.240
H2.C2 0.287 0.287

–
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For more options, visit https://groups.google.com/d/optout.