Re: [Help-glpk] Re: Help-glpk Digest, Vol 90, Issue 1

[glpk xypron]

Hello Greg,

the following expressions work when added to 
examples/transp.mod

solve;
display (demand['Topeka'].dual);
display {j in J} (demand[j].dual);

This does not:
display demand['Topeka'].dual;

I have added the following lines to
glpk-4.38-dot/src/glpmpl01.c

            if (mpl->token == T_POINT)
            {  error(mpl, "display statement does not support output of "
                  "properties here, use (indexed) expression instead");
            }

and committed to
http://glpk.dyndns.org/svn/glpk/branches/glpk-4.38-dot/

Best regards

Xypron


-------- Original-Nachricht --------
> Datum: Sun, 02 May 2010 12:54:29 +0200
> Von: "glpk xypron" <address@hidden>
> An: Greg Gruber <address@hidden>, address@hidden
> Betreff: Re: [Help-glpk] Re: Help-glpk Digest, Vol 90, Issue 1

> Hello Greg,
> 
> I tested with examples/transp.mod;
> 
> I can confirm, the following causes an error:
> display supply['Seattle'].dual;
> 
> printf supply['Seattle'].dual;
> works fine.
> 
> I will have a look what needs to changed in my patch.
> 
> Hopefully Andrew will at some time put support for outputting
> duals into the official release.
> 
> Best regards
> 
> Xypron
> 
> 
> -------- Original-Nachricht --------
> > Datum: Sat, 1 May 2010 23:58:41 -0400
> > Von: Greg Gruber <address@hidden>
> > An: address@hidden
> > Betreff: [Help-glpk] Re: Help-glpk Digest, Vol 90, Issue 1
> 
> > Hello,
> > I have a column-generation problem I'm trying to switch over from
> > AMPL/CPLEX
> > to GLPK, and it would be useful to be able to display the dual values in
> > MathProg.  I know that suffixes are not supported in the official
> release,
> > but I saw the following:
> > 
> > An unofficial patched version of a last year GLPK release can be
> > > checked out with subversion
> > >
> > > svn co http://glpk.dyndns.org/svn/glpk/branches/glpk-4.38-dot/
> > >
> > > It supports the following suffixes in the post solution phase:
> > >
> > > variables
> > > lb - lower bound
> > > ub - upper bound
> > > val - value
> > > dual - dual value
> > > basic - 1 if variable is basic
> > >
> > > constraints
> > > lb - lower bound
> > > ub - upper bound
> > > dual - dual value
> > > value - value
> > >
> > >
> > I downloaded this version using "vn co
> > http://glpk.dyndns.org/svn/glpk/branches/glpk-4.38-dot/";  then compiled
> it
> > (configure, make, make install).  The compile appears successful, and
> when
> > I
> > check the date/timestamp on my glpsol, it shows the current date/time. 
> > When
> > I try to use the ".dual" functionality as follows:
> > 
> > "display summation_constraint.dual;"
> > 
> > I get an error message:
> > 
> > "Reading model section from test_cur1_2.mod...
> > test_cur1_2.mod:67: invalid reference to constraint summation_constraint
> > Context: ...f MaxCHarn >> '...' ; solve ; display summation_constraint .
> > GLPK: model processing error"
> > 
> > Did I download the correct version?
> > 
> > Thanks,
> > Greg
> 
> -- 
> GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT!
> Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01
> 
> 
> _______________________________________________
> Help-glpk mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/help-glpk

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