Defining equation with logical condition on index

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Vivek
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Defining equation with logical condition on index

Post by Vivek » 6 months ago

Hi everyone,

I'm new to GAMS and since last few days I'm trying code an equation but finding it difficult to do so. In the equation j is an element which belong to intersection of 2 multidimensional sets i.e. JP(j*p) and JS(j*s). Below I'm attaching an image of the equation.
forum_doubt_1.JPG
forum_doubt_1.JPG (10.7 KiB) Viewed 565 times
Also, the code that I have developed for the above equation is as follows:

Code: Select all

Constraints8(s,p)..       sum(j,Y(s,j,p)) =e= 1; 
Please help if you know how to code this thing. It would be really helpful. Thanks.

abhosekar
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Re: Defining equation with logical condition on index

Post by abhosekar » 6 months ago

You can create multidimensional sets jp(j, p) and js(j, s). Find more information on multidimensional sets here: https://www.gams.com/latest/docs/UG_Set ... sionalSets

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set
jp /#j.#p/
js /#j.#s/
;
You can then write your constraint with if condition

Code: Select all

constraints8(s, p).. sum(j $(jp(j, p) and js(j, s)), Y(s, j, p)) =e= 1;
Not sure if it is relevant, but I also note that your equation is defined over p^in _p. If this is by any chance a subset of set P, you can define it as
set
p_in(p);

and then assign relevant elements to it.
Hope this helps!

- Atharv

Vivek
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Joined: 6 months ago

Re: Defining equation with logical condition on index

Post by Vivek » 6 months ago

Hi Athrav,

Thanks a lot for your suggestions, it worked. Also, I forgot to mention that P^in(P) is a subset of P but you have already assumed it correctly. Thank you for helping me out. :)

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