Re: [Help-glpk] Invalid type error for abs() function

[Andrew Makhorin]

>    I'm getting the following error when checking my MathProg model:
> 
> test.mod:50: argument for abs has invalid type
> Context:  ( abs ( map [ i , k ] * X [ k ] - map [ j , l ] * X [ l ] )
> Model processing error
> 
> where map is defined as:
> var map{i in MDFG, j in ADEPT}, binary;
> 
> and X is defined as:
> param X{k in ADEPT};
> 
> and the indices i,j,k,l are dummy indices coming from 3 sum statements
> like sum{i in MDFG, j in MDFG} sum{k in ADEPT} sum{l in ADEPT}
> 
> I haven't found anything in the doucmentation that would suggest to me
> that this is an invalid statement but I'm obviously missing something.
> 
> Any help is greatly appreciated.

Please see:

http://lists.gnu.org/archive/html/help-glpk/2004-07/msg00025.html

http://lists.gnu.org/archive/html/help-glpk/2004-07/msg00026.html