[Help-glpk] is there a function for count in MATHPROG?

[Rafael Torres]

I'm looking for a function that count number of objects that belong to a 
specific cluster but I dont know if such function exists.

For example I'm trying to count number of objects in variable Z[i] but 
with Cardinal function I get an error tha says "invalid preceding 
operator == "  what does it mean?

Thanks in advance.


This is my code:

# PARAMETROS
param noitems          ; # numero de items
param nometodos        ; # numero de metodos
#param nocategorias    ; # numero de categorias

# CONJUNTOS
set ITEMS            := 1..noitems            ; # Items
set METODOS            :=    1..nometodos        ; # Metodos
set CATEGORIAS        ; # Categorias


# DATOS
param clasini{i in ITEMS , j in METODOS} , integer    ;
param nocategorias := card(CATEGORIAS);
param Porcentaje{k in 1.. nocategorias} ;

# VARIABLES DE DECISION
#var Z{ITEMS} in CATEGORIAS , integer     ;
var Z{i in ITEMS}  ;

# VARIABLES AUXILIARES PARA LINEALIZAR
var T{i in ITEMS, j in METODOS}  ;


# MODELO MATEMATICO
    # Funcion objetivo
    minimize distance: sum{i in ITEMS , j in METODOS} T[i,j]    ;

    # Restricciones
    s.t. Positivo{i in ITEMS , j in METODOS }:  Z[i] - clasini[i,j] <= 
T[i,j]    ;
    s.t. Negativo{i in ITEMS , j in METODOS }: -Z[i] + clasini[i,j] <= 
T[i,j]    ;
    s.t. Proporcion{k in 1..card(CATEGORIAS)}: card({i in ITEMS: k in 
Z[i]}) <= noitems*Porcentaje[k];
solve;

--
Rafael Torres





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