## Loop

Problems with syntax of GAMS
baseerabbasi
User
Posts: 2
Joined: 10 months ago

### Loop

Hi,
I am working in power distribution side. In my GAMS code , I have multiply cost with PRESENT WORTH FACTOR [1/((1+r)**Y)] , where r=0.03 and "Y" is number of years. Now I want my GAMS code to print value for 5 years . It is like this..
COST(Y)*[1/((1+r)**Y)] . I can not get incremental value for every year and display it for every year.
Can anybody help me in this loop

Renger
Posts: 221
Joined: 2 years ago

### Re: Loop

Hi

It is not completely clear what you want (it is better to add some code you have already available).

Here some code to get every fifth element of a y as a subset by defining a subset y5(y). You define this dynamic set without assigning any values of y to it. This is done using the \$-operator and the mod function:

Code: Select all

``````set y years /2015*2050/
y5(y)   every fifth year;

y5(y)\$(mod(ord(y) - 1,5)=0) = YES;

display y5;
``````
Cheers
Renger

baseerabbasi
User
Posts: 2
Joined: 10 months ago

### Re: Loop

Hi,

My Code is like this
eq3.. Netcost=e=(costAC+costDC);
eq4.. PW=e=1/(1+r)**y;
eq5.. CostY1=e=Netcost*PW;
eq6.. CostY2=e=CostY1*PW;
eq7.. CostY3=e=CostY2*PW;

I want to make a loop that will increment year (y) value and calculate cost for the next year and then display it, A loop that give me Cost for each year from Y1 to Y5,

Thanks

Renger
Posts: 221
Joined: 2 years ago

### Re: Loop

Hi
If you want to loop over y, you should have indexed parameters, variables and equations. I think you should first sit down and derive mathematically what you want to do and then start from there: write down your model with model definition, solve statement, and have a good look at how to write indexed parameters, variables and equations.

CHeers
Renger