Re: [Bug-glpk] --nopresol does not stop presolver

[Andrew Makhorin]

Hi Xypron,

C:\>>glpsol.exe --dfs --nopresol -m s.mod

> gave the following output

> GLPSOL: GLPK LP/MIP Solver 4.39
> Reading model section from s.mod...
> 132 lines were read
> Generating start...
> Generating end...
> Generating onemove...
> Generating delta...
> Model has been successfully generated
> ipp_basic_tech:  66 row(s) and 66 column(s) removed
> ipp_reduce_bnds: 1 pass(es) made, 0 bound(s) reduced
> ipp_basic_tech:  0 row(s) and 0 column(s) removed
> ipp_reduce_coef: 1 pass(es) made, 0 coefficient(s) reduced
> glp_intopt: presolved MIP has 1054 rows, 3346 columns, 11404 non-zeros
> glp_intopt: 2356 integer columns, all of which are binary
> Scaling...

> The output was just the same if --presol is specified.

> I would have expected no column to be removed with --nopresol.

'--nopresol' disables the lp presolver; to disable the mip preprocessor
you should specify '--nointopt'.

PS: Thank you for your activity on the help-glpk list.