strict inequality

GAMS
1

hi

Is there anybody know how i can model strict inequality in gams?? i know =g= but i means strict one such as strict greater or lowre

please help me,

thanks alot

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2

Theoretically, all continuous optimization needs closed sets which requires the equal part. If not, the solution will just be the limit for the variable going towards it bound.



In practice, how strict do you want? If you have expr =G=1 is expr =1.000000001 OK?. If so, use expr =G= 1.00000001. But consider that the tolerance for the constraint probably is around 1.e-7.



If you have integer expressions it is much easier. Strictly less than 5 means less than or equal to 4.



Regards



Arne


\

Arne Stolbjerg Drud

ARKI Consulting & Development A/S

Bagsvaerdvej 246A, DK-2880 Bagsvaerd, Denmark

Phone: (+45) 44 49 03 23, Fax: (+45) 44 49 03 33, email: adrud@arki.dk



From: gamsworld@googlegroups.com [mailto:gamsworld@googlegroups.com] On Behalf Of saba
Sent: Friday, August 15, 2014 11:09 AM
To: gamsworld@googlegroups.com
Subject: strict inequality



hi



Is there anybody know how i can model strict inequality in gams?? i know =g= but i means strict one such as strict greater or lowre



please help me,



thanks alot

–
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3

hi
i think putting an =x= in the equation and defining equation in other programs may help you. but i’m not sure.
read page 566 of mccarl user guide.part 16.5(( Using equations defined by external programs))



On Friday, August 15, 2014 1:38:51 PM UTC+4:30, saba wrote:

hi

Is there anybody know how i can model strict inequality in gams?? i know =g= but i means strict one such as strict greater or lowre

please help me,

thanks alot

–
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4

Reply-to: gamsworld@googlegroups.com

Thanks dear arne



But I should notice that my case doesn’t include two items you said. Please help me for modeling this constraint :

lt(i)-at(i,k,p)+BN*a(i,k,p)=g=0

Lt is real parameter

At is real decision variable

Bn=big number

A is binary variable

If a=0 , at is lower than lt, ok? Its clear ,but I want strinct lower,it means forexample if lt is 100 ,at wouldnt be 100 . how I show it in explained constraint



regard

On Friday, 15 August 2014 14:04:33 UTC+4:30, Arne Stolbjerg Drud wrote:

Theoretically, all continuous optimization needs closed sets which requires the equal part. If not, the solution will just be the limit for the variable going towards it bound.



In practice, how strict do you want? If you have expr =G=1 is expr =1.000000001 OK?. If so, use expr =G= 1.00000001. But consider that the tolerance for the constraint probably is around 1.e-7.



If you have integer expressions it is much easier. Strictly less than 5 means less than or equal to 4.



Regards



Arne


\

Arne Stolbjerg Drud

ARKI Consulting & Development A/S

Bagsvaerdvej 246A, DK-2880 Bagsvaerd, Denmark

Phone: (+45) 44 49 03 23, Fax: (+45) 44 49 03 33, email: ad…@arki.dk



From: gams...@googlegroups.com [mailto:gams...@googlegroups.com] On Behalf Of saba
Sent: Friday, August 15, 2014 11:09 AM
To: gams...@googlegroups.com
Subject: strict inequality



hi



Is there anybody know how i can model strict inequality in gams?? i know =g= but i means strict one such as strict greater or lowre



please help me,



thanks alot

–
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5

Why not write

lt(i)0.999-at(i,k,p)+BNa(i,k,p)=g=0

If a = 0 and lt = 100 then at would be less than 99.9. You have to decide how close you want to go and then modify lt or add a factor to lt. Only you can decide how close you want to be. Is 99.9999 ok or do you need 99.0?



Arne


\

Arne Stolbjerg Drud

ARKI Consulting & Development A/S

Bagsvaerdvej 246A, DK-2880 Bagsvaerd, Denmark

Phone: (+45) 44 49 03 23, Fax: (+45) 44 49 03 33, email: adrud@arki.dk



From: gamsworld@googlegroups.com [mailto:gamsworld@googlegroups.com] On Behalf Of saba
Sent: Friday, August 15, 2014 7:58 PM
To: gamsworld@googlegroups.com
Cc: adrud@arki.dk
Subject: Re: strict inequality



Thanks dear arne



But I should notice that my case doesn’t include two items you said. Please help me for modeling this constraint :

lt(i)-at(i,k,p)+BN*a(i,k,p)=g=0

Lt is real parameter

At is real decision variable

Bn=big number

A is binary variable

If a=0 , at is lower than lt, ok? Its clear ,but I want strinct lower,it means forexample if lt is 100 ,at wouldnt be 100 . how I show it in explained constraint



regard


On Friday, 15 August 2014 14:04:33 UTC+4:30, Arne Stolbjerg Drud wrote:

Theoretically, all continuous optimization needs closed sets which requires the equal part. If not, the solution will just be the limit for the variable going towards it bound.



In practice, how strict do you want? If you have expr =G=1 is expr =1.000000001 OK?. If so, use expr =G= 1.00000001. But consider that the tolerance for the constraint probably is around 1.e-7.



If you have integer expressions it is much easier. Strictly less than 5 means less than or equal to 4.



Regards



Arne


\

Arne Stolbjerg Drud

ARKI Consulting & Development A/S

Bagsvaerdvej 246A, DK-2880 Bagsvaerd, Denmark

Phone: (+45) 44 49 03 23, Fax: (+45) 44 49 03 33, email: ad…@arki.dk



From: gams...@googlegroups.com [mailto:gams...@googlegroups.com] On Behalf Of saba
Sent: Friday, August 15, 2014 11:09 AM
To: gams...@googlegroups.com
Subject: strict inequality



hi



Is there anybody know how i can model strict inequality in gams?? i know =g= but i means strict one such as strict greater or lowre



please help me,



thanks alot

–
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