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GAMS sum and prod syntax_ what different?

Posted: Fri Jun 15, 2018 6:16 am
by m_tanawat
Hi all,

I read GAMS manual and find some unclear points.
I want to know what is the prod meaning in GAMS?
I know that it uses same sysntax as sum. But I am not sure what is it implying in economics.

Sum(j, x(j)) = x1+x2+x3+....xn
What prod(j, x(i, j)) is equivalent to?

Note that I see it uses with objective function.

obj.. UU =e= prod(i,x(i)**alpha(i));

Anyone, please help clarify me.
Thank you,

Re: GAMS sum and prod syntax_ what different?

Posted: Fri Jun 15, 2018 10:36 am
by Fred
Hi,

The product operation prod() represents the capital pi notation (see https://en.wikipedia.org/wiki/Multiplic ... i_notation).
This is similar to the sum operation sum() representing the captal sigma notation (https://en.wikipedia.org/wiki/Summation ... a_notation)

I hope this helps!

Fred

Re: GAMS sum and prod syntax_ what different?

Posted: Mon Jun 18, 2018 3:31 am
by m_tanawat
Hi Fred,

Many thanks for your reply.
I totally understand it now.

Best regards,

Re: GAMS sum and prod syntax_ what different?

Posted: Sat Jul 20, 2019 9:47 am
by rejinsr037
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