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st: Constructing a variable: sum of a var over all j's (if j does not equal i)


From   "Sven P. Jost" <[email protected]>
To   [email protected]
Subject   st: Constructing a variable: sum of a var over all j's (if j does not equal i)
Date   Fri, 6 Nov 2009 10:04:24 +0100

Hello everybody,

I am currently experiencing a problem with the construction of a variable.

Please consider the following: There are multiple cars in a city i.
Further consider that the number of cars in city i depends on a
weighted measure as given on the right hand side below (whereas i does
not equal j)):

Cars in city i = ... + SUM of [ (Cars in city j / Cars in all cities)
x car dealers in city j ] over all j's.

Please note that there is a variable car_loc indicating that a car is
registered in a specific city.

We are now interested in constructed the variable on the right hand
side which, as far as I can tell, consists of three parts : (i) the
sum of all cars in cities j (ii) the sum of cars in all cities (iii)
and the sum of gas stations in cities j.

Thank you for all your help in advance.

Regards,
Sven

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