[Help-glpk] Concatenate Parameter "Fields" Question

[Robert A Schroeder]

I’m currently importing demand as a set of SKU(s), City(c ), State(s), TransMode(m) tuple parameters.  I’d like to eliminate a dimension by concatenating the City and State into one element.  I see how to do this for a set:

 

set LOC := setof{(s, c, st, m) in DMD_t}(c&", "&st);  #the set of valid City/State combination

 

set DMD := setof{(s, c, st, m) in DMD_t}(s, c&", "&st, m);  #The demand set: SKU, City/State, Mode

 

Where DMD_t is my temporary demand set of imported data with dimension 4, and DMD is the 3 dimension set I’d like to work with in the model.

 

My question: Is there a similar construct for converting a 4-tuple parameter to a 3-tuple?

 

That is, can I somehow convert:

Parameter Demand_t[s, c, st, m] to Parameter Demand[s, l, m] by concatenating the city and state dimenstions.

 

I realize I could concatenate the fields in my input data, but I’m curious if there is a way to accomplish this with parameter manipulation.  I’m new to glpk, so apologies in advance if this is a silly question.

 

Thanks for your help,

Rob