Hi，Renger
Thanks for your help.
Best regards
Hiking
2014å¹´11月26æ—¥ 下åˆ7:29于 “Renger van Nieuwkoop” 写é“：
Hi Hiking
If you only use sita for summing in this one equation, you don’t need the set sita.
You can control the summing over the proper set elements by using k to indicate which variables should be summed. k in your example is either 0 (no summation), 2, or 3.
Here an example, where k is used to control the number of previous periods.
If I understand the equation correctly, the variable y should be defined over (c,m,mp,h) and not over c(c,mp,h).
Cheers
Renger
set
h the set of hours in the operational model /1*10/ ,
c the sets of components exchanger1 and exchanger2/ex1,ex2/,
m modes of c e.g high temperature mode and low temperature mode /off,cold,warm,high,low/
i /bottom, top/;
;
alias(m,mp), (c,cp), (h,hh);
Parameters
K(c,m,mp) / ex1.cold.low 2,
ex1.low.off 2,
ex1.high.off 3,
ex2.cold.low 2,
ex2.low.off 2,
ex2.high.off 3/;
** Use parameters instead of variables to check the equation easily
parameter
y(c,m,mp,h),
z(c,m,mp,hh);
** Initialize z:
z(c,m,mp,hh) = 1;
y(c,m,mp,h)k(c,m,mp) = sum(hh(ord(hh)+k(c,m,mp) > ord(h) and ord(hh) :
hello Renger,
Iam sorry for my rough code .I have overwrited my code ,the set i had been added,and the = had been replaced with =g= as the model demands and so as to the semicolons in the code .But Renger, I think you mistaken what confused me .sita as you can see in the picture attachment should be a fixed sets like sita(c,m,mp) consists of several subsets like /0,1,2…K(c,m,mp)/ .but as you know it is wrong in syntax and cant be formulated like this .In your example hh consists of only one subset ( it is my definition ) ,how can I express it if hh is a parameter like hh(i) (e.g if i =1 ,hh(i)=4;i=2,hh(i)=5;i=3,hh(i)=6),and to get the sum of z(sita) where sita is from 0 to hh(i) .
best regards
Hiking
在 2014å¹´11月25日星期二UTC+8下åˆ7æ—¶14分14秒，qinghai Sun写é“：
Hello,
I occured a problem how to write the sum expression.my code is followed ：
set i the extreme points /top,buttom/ ;
set c the sets of components exchanger1 and exchanger2/ex1,ex2/;alias(c,cp);
set m modes of c e.g high tempreture mode and low tempreture mode /off,cold,warm,high,low/ alias(m,mp,mpp);
set p products /tem,hot/ ;alias(p,g ,pp);
set dal(c,m,mp) disallowed transitions/(ex1,ex2).(off.low,off.high,cold.off,cold.high,warm.off,warm.high,low.cold,low.warm,high.warm,high.cold,high.off)/;
set ms(c,m,mp) minimum stay /(ex1,ex2).(cold.low,low.off,high.low)/;
set h the set of hours in the operational model /1*100/ ;
Parameters
x(c,m,i,p) /ex1.low.top.tem 180,
ex1.low.buttom.tem 120,
ex1.high.top.tem 320,
ex1.high.buttom.tem 180,
ex2.low.top.hot 180,
ex2.low.buttom.hot 120,
ex2.high.top.hot 320,
ex2.high.buttom.hot 180/
K(c,m,mp) / ex1.cold.low 2,
ex1.low.off 2,
ex1.high.off 3,
ex2.cold.low 2,
ex2.low.off 2,
ex2.high.off 3/
Equations
minStay(c,mp,h) minimum stay constraint;
minStay(c,mp,h)$(ms(c,m,mp)) … y(c,mp,h) =g= sum(sita,z(c,m,mp,h-sita+1)) where sita I think should be a set .but in the expression demanded sita is a set for 1 to K(ms) .I am confused how to define sita in Gams ,for it is assicated with K(ms) .the expression I am trying to formulated can be seen in the attachment for it cant write directly in the editor .
Thanks in advance .
Hiking
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