Comparing subset with parameter in constraint

[rasa raufi]

Dear All,

I have a LP model, which have defined time horizon in it, in one of the constraint I have to make a comparison between the current time horizon and another parameter ( time transportation takes from point A to B).

Unfortunately dont know how to set this Using AIMMS ( already have tried different tricks like a subset of ''t'' but didnt worked out and i got the error :
There is no operation defined for operator ">" with arguments of data type set and data type numeric; the arguments themselves are "TH(t)" and "TT(k,d)".

I have attached the model in word, and my current written constraint is:

sum(c,TX(d,c,t)+ETY(d,c,t))-sum[(c,k)|k<>d AND TH(t)>TT(k,d),TX(k,d,(TH(t)-TT(k,d)))+ETY(k,d,(TH(t)-TT(k,d)))]-ETY(d,d,(TH(t)-1))-ETY(d,d,(TH(t)-1))=FAVT(d,t)

The Bold part, where error is happening, here TH(t) is a subset of time{t} which is defined as planning horizon in the model, and TT(k,d) is parameter showing how long takes from point k to d.

Thank you very much for your help in advance.

Best,

Rasa.

[Chris Kuip]

Hi Rasa,

Is TH a subset of integers?

Best,

Chris. 

Op zondag 9 juni 2013 09:56:35 UTC+2 schreef rasa raufi het volgende:

[rasa raufi]

Hi Chris,

TH is subset of Time which is defined as : Elementrange( from:1, to:24) 
I`m not 100% sure if it explicitly means that it's an integer though.

I have attached the text file of the model so you can see how I defined Time and TH.

Thanks a lot for helping me with this in advance.

Best,

Rasa.

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[Chris Kuip]

Hi Rasa,

For the set Tme, I think you want: 

- to add 'Integers' to the subset of attribute

- to remove the prefix: "Horizon" from the call to ElementRange in the definition attribute.

This will make your time set Tme both integer and thus numeric and a discrete finite set.

Because the set is numeric AIMMS will allow you to compare its elements using the ">" operator with a numeric parameter.

Note that with this change, the elements of Tme will be 1, 2, 3, ... instead of Horizon1, Horizon2, ... .

Best,

Chris.

Op zondag 9 juni 2013 09:56:35 UTC+2 schreef rasa raufi het volgende:

Dear All,

[rasa raufi]

Hi Chris, 

Thanks for the trick! I believe this is going to be the situation, just another question ( maybe a bit simple but i`m new using AIMMS), how should i add integer to the subset of attribute?  ( assume need to define in the definition part but could you let me know how to?)

Kind regards,

Rasa.

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[Chris Kuip]

Hi Rasa,

Click the wizard button just to the at the "subset of" attribute.

Type in Integers

Click the button with the double down arrow

Click ok

Best,

Chris

Op zondag 9 juni 2013 09:56:35 UTC+2 schreef rasa raufi het volgende:

Dear All,

[rasa raufi]

Dear Chris, If I do it, then TH wont be anymore subset of Time (t), it will be a subset of Integers, right?

Unfortunately tried it in the constraint and still have the same error there.

Isn`t possible for TH to be both subset of Time and Integers?

Best,

Rasa

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[Chris Kuip]

Hi Rasa,

I suggest to let TH stay a subset of Tme, Tme should become a subset of Integers. Thus, yes, TH becomes a subsest of both Tme and Integers in this way.

Hope this helps,

Chris.

Op zondag 9 juni 2013 09:56:35 UTC+2 schreef rasa raufi het volgende:

Dear All,

[rasa raufi]

Dear Chris,

I have tried that, so now time is a subset of Integers, and TH is subset of time, but still have the same error unfortunately ( on the same spot- TH(t) ). Any Idea?- Its getting really annoying at this point with this error.

All the best,

Rasa.

[Chris Kuip]

Hi Rasa,

Can you publish your project in this forum, then I'll have a look at it.

Best,

Chris.

Op zondag 9 juni 2013 09:56:35 UTC+2 schreef rasa raufi het volgende:

Dear All,

[rasa raufi]

Goodmorning Chris, 

Herewith I attached the project (including all files).

Thank you very much in advance.

Kind regards,

Rasa.

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[rasa raufi]

Dear Chris, 

Sorry for the inconvenience, this is the latest version of the project ( with the details that we have discussed).

[Chris Kuip]

Hi Rasa,

With your project it becomes more clear.

At the identifier TH you have specified the index domain attribute; you have made that set an indexed set.  

So the reference TH(t) is also a set and with the expression "TH(t)>TT(k,d)" you are comparing a set to a number.  

Hope this clarifies things.

Best regards,

Chris.

Op maandag 10 juni 2013 08:48:56 UTC+2 schreef rasa raufi het volgende: