Syntax error

Problems with syntax of GAMS
nasim
User
Posts: 8
Joined: 3 years ago

Syntax error

Hello
I m writing a simple farm profit maximization model. I wrote the simple form and I got the answer which means that the model works, but when I used set notation to define variables I got many Syntax errors. Below is the model. would you please help me? I cannot understand where is the problem.

option sysout=off;

sets
i "option" /p,b,s,d/
j "products" /c,l,m/
k "type of product" /1,2,3,4,5,6,7,8,9,10,11,12,13,14/;

Alias (i,ii,iii)

variables
z total farm profit
x(i,j,k) amount of produced bought sold or distributed of each type of crop livestock or manure;

parameters
y(k) profit of each crop type/

"1" 937.45
"2" 9712.7
"3" 1011.43
"4" 10156.57
"5" 1085.41
"6" 10600.44
"7" 1140.89
"8" 10933.34
"9" 1002.13
"10" 118.03
"11" 484.42
"12" 365.39
"13" 532.91
"14" 0
/

equations

OBJ
land1
land2
machin1
machin2
machin3
machin4
livestock1
livestock2
feeding1
feeding2
feeding3
feeding4
rotation1
rotation2
rotation3
rotation4
rotation5
disposal1
disposal2
disposal3

OBJ..z=E= sum(k, x(p,c,k)* y(k)) + 1849*x(p,l,1)+ 53854*x(p,l,2)- 258.5*x(b,c,1) - 258.5*x(b,c,2) - 205.7*x(b,c,9) +15.70*x(s,m,3) -3.374*x(d,m,1) - 6.90*x(d,m,2);
land1.. sum(k\$ x(p,c,k) lt14 ,x(p,c,k))=L=400;
land2.. x(p,c,14)=L=23;
.
.
.
the errors show problem with the firm line of OBJ function!!

Thank you so much

Renger
Posts: 550
Joined: 3 years ago

Re: Syntax error

Hi
If you write x(p,c,k), you probably mean x("p", "c",k). If you want to use specific set elements in an expression, you should use it like shown.
Cheers
Renger
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