Problem with loop

GAMS
1

Dear all,

I am trying to perform few calculations using loop. However, the formulated syntax is not able to store the last value of parameter b(z) (722) to set u2(zz). Please see the attached model for more details. I will really appreciate it if someone helps me with correcting the codes.
syntax.gms (459 Bytes)
Best regards,
Rofice

2

Hi,

B(z+1) is declared in the same loop as u2(zz), so in the last loop iteration B(z+1) will have a value (772) but u2+1 won’t.
One way to solve this is to declare u2(zz+1) in the same loop, but keep in mind that now you will miss the first value of u2(zz), but just like the first b-value you can also initialize the first u2 value with the same value as b.

Cheers,
GFA

set z  hours in a year / 1*8760 /

 alias (z,zz);

 scalar init stopping criteria ; init = 0;

 parameter

 a(z) number of days in january ,

 b(z) add interval of 24 hours ;

 set u2(zz) feasible elements should equal to b(z) ;

 init = 0;  a('1') = 1 ; b('1') = 2  ;
 u2("2") = yes;

 loop(z $ (init ne 1) ,

 a(z+1) = a(z) + 1;

 b(z+1) = b(z) + 24;

 u2(zz+1) $ (ord(zz)+1=b(z+1))  = yes ;

 init $ {a(z+1) eq 31} = 1;

 ) ;


 display a,b,u2;
3

Thanks GFA!

Best regards,
Rofice