re: [Help-glpk] Re: computational efforts, message level and KKT

[Robbie Morrison]

Hi all

>> >>   int niter = lpx_get_int_parm(d_prob, LPX_K_ITCNT); // lpx is correct
>> >>
>> >> Are you sure the call is broken? But I agree, it would
>> >> be better if the API was updated.
>> >
>> > Last time I checked it always returned zero. Maybe I messed up
something...
>>
>> I just double checked with 4.44.  You are correct.  Zero iterations!
>> That is relatively recent I think.
>
> Just checked the code and found a bug. To fix it please remove the
> following line in the local routine reset_parms, file src/glplpx01.c:
>
>       lp->it_cnt   = 0;

Just tested the given patch.  Before and after:

    simplex iterations              :       0
    simplex iterations              :      10

Just one small word of caution.  Make sure you test
this patch on a problem that is sufficiently complex to
generate some iterations and cannot simply be solved by
the presolver.  :-)

Great!  Thanks Andrew.

---
Robbie Morrison
PhD student -- policy-oriented energy system simulation
Technical University of Berlin (TU-Berlin), Germany
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