Hi there,

My problem is about calculating the endpoint of a set(not a static predefined) in the problem constraints.

My code is:

obj… blabla

.

.

eLfp… Lfp =e= sum(k,(0.7 * Df) + (0.7 * Df * sqrt(3) * (i-1)) + Df * sqrt(3)) ;

eLfo… Lfo =e= sum(k,(i-1) * 0.7 * Df) ;

ek… k =e= ((Lc - Df * sqrt(3) - 0.7 * Df ) / (0.7 * Df * sqrt(3) )) + 1;

.

.

I try to let the solver come up with a k value and then use it as an index in other constraints.

I also wrote "Set i number of cycles /1*k/; ", but it doesnt work

## I need help! Thanks for your kind attentions…

\

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k is a set?

On Sun, Jan 6, 2013 at 7:08 AM, wrote:

Hi there,

My problem is about calculating the endpoint of a set(not a static predefined) in the problem constraints.

My code is:

obj… blabla

.

.

eLfp… Lfp =e= sum(k,(0.7 * Df) + (0.7 * Df * sqrt(3) * (i-1)) + Df * sqrt(3)) ;

eLfo… Lfo =e= sum(k,(i-1) * 0.7 * Df) ;

ek… k =e= ((Lc - Df * sqrt(3) - 0.7 * Df ) / (0.7 * Df * sqrt(3) )) + 1;

.

.

I try to let the solver come up with a k value and then use it as an index in other constraints.

I also wrote "Set i number of cycles /1*k/; ", but it doesnt work

## I need help! Thanks for your kind attentions…

\

Babak Saleck Pay

M.Sc

Socio-Economic System Engineering

Group of Industrial Engineering

University of Tehran

Tehran,Iran

www.babaksp.com

–

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For as far as I know, k does not need to be a set, it needs to be an element of the set you investigate.

As it is neither (it’s a variable, whose value is defined in an equation), your idea won’t work (unfortunately).

Maybe setting a sufficiently large set will work, which you sum for all the elements lower then your value of k.

## So, make sure something like this is in your model as well:

sets k1 very large set size /1*200/

variable

k2;

k2.l=1;

…

equations…

eLfp… Lfp=e=sum(k1,(…)Â§(ord(k1) wrote:

Hi there,

My problem is about calculating the endpoint of a set(not a static predefined) in the problem constraints.

My code is:

obj… blabla

.

.

eLfp… Lfp =e= sum(k,(0.7 * Df) + (0.7 * Df * sqrt(3) * (i-1)) + Df * sqrt(3)) ;

eLfo… Lfo =e= sum(k,(i-1) * 0.7 * Df) ;

ek… k =e= ((Lc - Df * sqrt(3) - 0.7 * Df ) / (0.7 * Df * sqrt(3) )) + 1;

.

.

I try to let the solver come up with a k value and then use it as an index in other constraints.

I also wrote "Set i number of cycles /1*k/; ", but it doesnt work

## I need help! Thanks for your kind attentions…

\

Babak Saleck Pay

M.Sc

Socio-Economic System Engineering

Group of Industrial Engineering

University of Tehran

Tehran,Iran

www.babaksp.com

–

To view this discussion on the web visit https://groups.google.com/d/msg/gamsworld/-/33FL6rxxsr0J.

To post to this group, send email to gamsworld@googlegroups.com.

To unsubscribe from this group, send email to gamsworld+unsubscribe@googlegroups.com.

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I forgot to see that in my response that equation “eLfo” is uncontrolled (and therefore needs to be checked multiple times), which makes it nonlinear.

So, unless you have a solver that can handle that, a loop (which scans the entire set k1) would be more advisable.

On Monday, January 7, 2013 4:29:03 PM UTC+1, B.Saleckpay wrote:

k is a set?

On Sun, Jan 6, 2013 at 7:08 AM, wrote:

Hi there,

My problem is about calculating the endpoint of a set(not a static predefined) in the problem constraints.

My code is:

obj… blabla

.

.

eLfp… Lfp =e= sum(k,(0.7 * Df) + (0.7 * Df * sqrt(3) * (i-1)) + Df * sqrt(3)) ;

eLfo… Lfo =e= sum(k,(i-1) * 0.7 * Df) ;

ek… k =e= ((Lc - Df * sqrt(3) - 0.7 * Df ) / (0.7 * Df * sqrt(3) )) + 1;

.

.

I try to let the solver come up with a k value and then use it as an index in other constraints.

I also wrote "Set i number of cycles /1*k/; ", but it doesnt work

## I need help! Thanks for your kind attentions…

\

Babak Saleck Pay

M.Sc

Socio-Economic System Engineering

Group of Industrial Engineering

University of Tehran

Tehran,Iran

www.babaksp.com

–

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