Re: [Help-glpk] MIPGAP error with Octave

[Marcelo Pinto]

Hi Andrew,

Thanks for reply. The source file __glpk_.cc follows attached.
Take a look at the output of my octave code using the __glpk__.cc modified:

GLPK Simplex Optimizer, v4.43
99 rows, 288 columns, 5280 non-zeros
Preprocessing...
99 rows, 288 columns, 5280 non-zeros
Scaling...
 A: min|aij| =  1.000e+00  max|aij| =  1.000e+00  ratio =  1.000e+00
Problem data seem to be well scaled
Constructing initial basis...
Size of triangular part = 99
      0: obj =   0.000000000e+00  infeas =  4.266e+03 (0)
*   107: obj =   1.897850000e+05  infeas =  0.000e+00 (0)
*   127: obj =   1.825400000e+05  infeas =  0.000e+00 (0)
OPTIMAL SOLUTION FOUND
GLPK Integer Optimizer, v4.43
99 rows, 288 columns, 5280 non-zeros
288 integer variables, none of which are binary
Integer optimization begins...
+   127: mip =     not found yet >=              -inf        (1; 0)
+   317: >>>>>   1.826200000e+05 >=   1.825400000e+05 < 0.1% (51; 0)
+   317: mip =   1.826200000e+05 >=   1.825400000e+05 < 0.1% (45; 10)
RELATIVE MIP GAP TOLERANCE REACHED; SEARCH TERMINATED


@address@hidden

STATUS = 215.000000
FMIN = nan

@address@hidden


Note that the 'STATUS' and 'FMIN' above are printed from just after
calling glpk() routine from __glpk__.cc

Tks,
Marcelo.

On Thu, Mar 31, 2011 at 8:00 AM, Andrew Makhorin <address@hidden> wrote:
>> As I need the mipgap for my application, I have added the the
>> param.mipgap to the octave's interface module (__glpk__.cc). However,
>> the glpk() API function returns "NA" values and the status 215.
>>
>> Can someone help me about how could I do to copy back the solution
>> (fmin, xmin) from glpk API when mipgap is set?
>
> Please provide a link to your version of __glpk__.cc (or post this file
> to me). Thanks.
>
>
> Andrew Makhorin
>
>