Search found 68 matches

by bussieck
5 days ago
Forum: Syntax
Topic: Using GAMS on Mac OS X Environment with Wine bottler
Replies: 9
Views: 112

Re: Using GAMS on Mac OS X Environment with Wine bottler

Hi, GAMS Studio is about to be released (in a month or two) in it's first version (see https://forum.gamsworld.org/viewtopic.php?f=8&t=10198#p23354 ). In the meantime you might want to check the contributed software page with some alternative UI for GAMS: https://www.gams.com/community/contributed-s...
by bussieck
6 days ago
Forum: Syntax
Topic: Using GAMS on Mac OS X Environment with Wine bottler
Replies: 9
Views: 112

Re: Using GAMS on Mac OS X Environment with Wine bottler

Hi,

gdxxrw (tool to read/write and write Excel files) requires native Windows and Excel installed. So you either generate the GDX file on your Windows box and move them over to your Mac or you resort to more platform independent formats like CSV.

Hope this helps,
-Michael
by bussieck
6 days ago
Forum: Modeling
Topic: Equilibrium modelling - GAMS vs Mathematica
Replies: 2
Views: 38

Re: Equilibrium modelling - GAMS vs Mathematica

A value of 3.61 can't be right. If you do the reverse calculation you get: pc.l = 3.61; $ondotl; qcdx.l = 4123029.1453/(pc**(0.5)); qcdd.l = 10259876.724/(pc**(0.1)); qcst.l = (9552850.67262715*(pc**(0.4)))/(1.14**(0.4)) ; scalar sumqcdxqcdd; sumqcdxqcdd = qcdx + qcdd; display sumqcdxqcdd, qcst.l; y...
by bussieck
1 week ago
Forum: Solvers
Topic: **Infeasible solution
Replies: 1
Views: 112

Re: **Infeasible solution

Hi, The constraint "Ch_DCh(i) .. Pch(i)*Pdch(i) =e= 0;" make the model non-convex and hard to debug (you need a global solver). Since the rest of the model is linear you should implement the logic with a binary variable: binary variable b(i); Ch_DCh1(i) .. Pch(i) =l= b(i)*bigM; Ch_DCh2(i) .. Pdch(i)...
by bussieck
1 week ago
Forum: Modeling
Topic: Constraint with present and next time state
Replies: 4
Views: 150

Re: Constraint with present and next time state

You should check the documentation for lag and lead: https://www.gams.com/latest/docs/UG_Ord ... dOperators

-Michael
by bussieck
2 weeks ago
Forum: Announcements
Topic: GAMS Distribution 25.0.2 (Maintenance Release) Announcement
Replies: 0
Views: 72

GAMS Distribution 25.0.2 (Maintenance Release) Announcement

​​Hi GAMS Users,

We started distributing GAMS Release 25.0.2 on January 31, 2018. This is a maintenance release.

You can download the software from https://www.gams.com/download/

Here are the release notes: https://www.gams.com/latest/docs/RN_250.html

Your GAMS Team
by bussieck
1 month ago
Forum: Announcements
Topic: GAMS Distribution 25.0.1 Announcement
Replies: 0
Views: 128

GAMS Distribution 25.0.1 Announcement

Hi GAMS Users,

We started distributing GAMS Release 25.0.1 on January 17, 2019.

You can download the software from https://www.gams.com/download/

Here are the release notes: https://www.gams.com/latest/docs/RN_250.html

Your GAMS Team
by bussieck
1 month ago
Forum: Modeling
Topic: Binary variable modelling
Replies: 2
Views: 192

Re: Binary variable modelling

Priyanka, I can see a problem with these constraints. ch_dis_lobinary is superfluous, but that's okay. When you say that "I am not getting the correct results" what do you mean. Do you have both I_ch and I_dist 1, or are the Pch and Pdis not 0 or between bounds? First of all make sure you get an opt...
by bussieck
1 month ago
Forum: Announcements
Topic: GAMS Distribution 25.0.0 (Beta Version) Announcement
Replies: 0
Views: 131

GAMS Distribution 25.0.0 (Beta Version) Announcement

Hi GAMS Users, We would like to announce the availability of the GAMS Distribution 25.0.0 (Beta Version). Please consult the beta release notes for details about new features and updated solvers: https://www.gams.com/25.0/docs/RN_250.html If you are interested in experimenting with this beta release...
by bussieck
1 month ago
Forum: Syntax
Topic: Logic assignment for parameters
Replies: 2
Views: 214

Re: Logic assignment for parameters

This seems to work: set n /1*10/; parameter Mn(n) /#n 0/; loop(n, Mn(n)$(mod(n.val,2)=1) = n.val-2 + Mn(n-((n.val+1)/2)) + Mn(n-((n.val-1)/2)); Mn(n)$(mod(n.val,2)=0) = n.val-2 + 2*Mn(n-(n.val/2)); ); display Mn; This gives: ---- 7 PARAMETER Mn 1 -1.000, 2 -2.000, 3 -2.000, 4 -2.000, 5 -1.000, 7 1.0...