## Please check my code. I have no idea what's wrong with it

Problems with syntax of GAMS
Seoms
User Posts: 2
Joined: 3 years ago

### Please check my code. I have no idea what's wrong with it

Hi I'm a newbe of GAMS and I want to figure out optimal solution X1 and X2 (both of them must be integer)
I think it is quite simple problem but I'm struggling with it.
Please find out wrong sentence and give me help.

\$TITLE Test Problem
\$OFFSYMXREF
\$OFFSYMLIST

VARIABLES X1, X2, Z
POSITIVE VARIABLES X1, X2;

EQUATIONS CON1, CON2, CON3, OBJ;
CON1.. 1*(X1) =L= 48;
CON2.. X2 =L= 48;
CON3.. (1-((0.2)**(X1))) + ((0.2)**(X1))*(1-((0.3)**(X2))) =G= 0.99;
OBJ.. Z =E= 1*60*(X1) + ((0.2)**(X1))*(X2)*(20);

X1.L = 0;
X2.L = 0;

MODEL ENGAGEMENT / ALL /;

SOLVE ENGAGEMENT USING RMINLP MINIMIZING Z;

petros.p
User Posts: 10
Joined: 3 years ago

### Re: Please check my code. I have no idea what's wrong with it

Hi,

Your problem is a mixed integer non linear program (MINLP). I used Baron to solve it and I think it is free for for a limited number of variables. Run the code below and tell me if it works:

Code: Select all

``````\$TITLE Test Problem
\$OFFSYMXREF
\$OFFSYMLIST

integer VARIABLES X1, X2   ;
variable Z;

EQUATIONS CON1, CON2, CON3, OBJ;
CON1.. 1*(X1) =L= 48;
CON2.. X2 =L= 48;
CON3.. (1-((0.2)**(X1))) + ((0.2)**(X1))*(1-((0.3)**(X2))) =G= 0.99;
OBJ.. Z =E= 1*60*(X1) + ((0.2)**(X1))*(X2)*(20);

X1.lo = 0;
X2.lo = 0;

MODEL ENGAGEMENT / ALL /;

options MINLP = Baron

SOLVE ENGAGEMENT USING MINLP MINIMIZING Z;``````
Best,
Petros

Seoms
User Posts: 2
Joined: 3 years ago

### Re: Please check my code. I have no idea what's wrong with it

petros.p wrote:
3 years ago
Hi,

Your problem is a mixed integer non linear program (MINLP). I used Baron to solve it and I think it is free for for a limited number of variables. Run the code below and tell me if it works:

Code: Select all

``````\$TITLE Test Problem
\$OFFSYMXREF
\$OFFSYMLIST

integer VARIABLES X1, X2   ;
variable Z;

EQUATIONS CON1, CON2, CON3, OBJ;
CON1.. 1*(X1) =L= 48;
CON2.. X2 =L= 48;
CON3.. (1-((0.2)**(X1))) + ((0.2)**(X1))*(1-((0.3)**(X2))) =G= 0.99;
OBJ.. Z =E= 1*60*(X1) + ((0.2)**(X1))*(X2)*(20);

X1.lo = 0;
X2.lo = 0;

MODEL ENGAGEMENT / ALL /;

options MINLP = Baron

SOLVE ENGAGEMENT USING MINLP MINIMIZING Z;``````
Best,
Petros
Thanks petros.p I tried your code but I got same error message.
Exec Error at line 22 : Problem extracting Short path, result contains extended ASCII codes

Aminz
User Posts: 5
Joined: 4 years ago

### Re: Please check my code. I have no idea what's wrong with it

Hi Seoms
I have the same problem as well. did you find the solution????

abhosekar
Moderator Posts: 288
Joined: 2 years ago

### Re: Please check my code. I have no idea what's wrong with it

Can you at least show the "full" error message? Provide more useful details (where you are running the model from, version of GAMS, etc.. ).

- Atharv