Re: [Help-glpk] suffixes in mathprog

[glpk xypron]

Hello Andrew,

thanks for implementing suffixes in GLPK.

Some problems still have to be resolved:

== Compilation ==

The prerelease does not compile under Windows 32bit:

glpk_4_44.def : error LNK2001: unresolved external symbol _glp_ksp_mt1
glpk_4_44.def : error LNK2001: unresolved external symbol _glp_skpgen

Compilation was possilble after removing these symbols from the
definition file.

== Display statement ==

=== After solve ===

I tested by modifying examples/transp.mod

In glpk-4.43

solve;
display demand["Topeka"];

resulted in 

Display statement at line 46
demand[Topeka] >= 275:
   1 x[San-Diego,Topeka]
   1 x[Seattle,Topeka]

In glpk-4.44 the output is

Display statement at line 46
275

I expect the display statement only to output the value of a 
constraint when the suffix .val is appended.

In GLPK 4.44

solve;
display {i in I, j in J} x[i,j].dual;

results in

Display statement at line 45
x[Seattle,New-York].val = 50
x[Seattle,Chicago].val = 300
x[Seattle,Topeka].val = 0
x[San-Diego,New-York].val = 275
x[San-Diego,Chicago].val = 0
x[San-Diego,Topeka].val = 275

I expect the dual value to be output.

=== Before solve ===

In glpk-4.43 it was allowable to write:

display demand["Topeka"];
solve;

resulting in output

Display statement at line 44
demand[Topeka] >= 275:
   1 x[San-Diego,Topeka]
   1 x[Seattle,Topeka]

In glpk-4.44 an error occurs

..\examples\transp.mod:44: invalid reference to status, primal value, or dual 
value of constraint de
mand above solve statement
Context: ...i in I } x [ i , j ] >= b [ j ] ; display demand [ '...' ] ;

In glpk-4.43 it was allowable to write:

display x;
solve;

resulting in 

Display statement at line 44
x[Seattle,New-York] >= 0
x[Seattle,Chicago] >= 0
x[Seattle,Topeka] >= 0
x[San-Diego,New-York] >= 0
x[San-Diego,Chicago] >= 0
x[San-Diego,Topeka] >= 0

In glpk-4.44 an error occurs:

..\examples\transp.mod:44: invalid reference to variable x above solve statement
Context: ...in J } : sum { i in I } x [ i , j ] >= b [ j ] ; display x ;
MathProg model processing error

Best regards

Xypron

-------- Original-Nachricht --------
> Datum: Sun, 16 May 2010 13:11:19 +0400
> Betreff: [Help-glpk] suffixes in mathprog

> I have implemented the suffixes in MathProg.
> 
> It would be nice if someone who is using this feature (due to Xypron)
> could test my implementation. The glpk tarball can be downloaded from
> http://sourceforge.net/projects/noumenon/files/ (please note that this
> is a non-official prerelease). Thanks.
> 
> Andrew Makhorin

-- 
GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT!
Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01