GAMS World Forum

Posted: **Thu Jun 06, 2019 5:43 pm**

Hi there,

How can I use the sum function only from the second or later period (t=2) instead of all t? sum(t, periodutility(t))

Cheers

Posted: **Fri Jun 07, 2019 1:11 pm**

Assuming that t is an orderd set (https://www.gams.com/latest/docs/UG_OrderedSets.html), you could use the ord operator:

 sum(t$(ord(t)>=2), periodutility(t))

I hope this helps!

Fred

Posted: **Fri Jun 07, 2019 2:08 pm**

Thanks again Fred!

Sum function from t=2