[Osi] Is there a way to deactivate solver output?

[Stefan Vigerske]

Hi,

> Applying the tricks you gave above, I was able to deactivate output
> for most solvers, except Xpress. Is there a chance I can also
> deactivate that?

I guess OsiXpr does not check for the loglevel in the message handler or
the OsiDoReducedPrint flag. It would be nice if you could file a ticket
at the Osi trac page (as soon as the coin server is up again).
As a workaround, you can write your own message handler (derived from
CoinMessageHandler) which just do nothing in its ::print() function. If
you pass that one into OsiXpr, then the output of Xpress should be
directed to there.

Stefan

> 
> #------------------------------------
> #Stuff I want to get rid of:
> #------------------------------------
> 
> Reading Problem _xprs_
> Problem Statistics
>            0 (      0 spare) rows
>            0 (      0 spare) structural columns
>            0 (      0 spare) non-zero elements
> Global Statistics
>            0 entities        0 sets        0 set members
> 
> Reading Problem Prob1
> Problem Statistics
>          600 (     50 spare) rows
>          927 (      0 spare) structural columns
>         2196 (    100 spare) non-zero elements
> Global Statistics
>            0 entities        0 sets        0 set members
> Presolved problem has:    382 rows     676 cols    1676 non-zeros
> Crash basis containing 187 structural columns created
> 
>    Its         Obj Value      S   Ninf  Nneg        Sum Inf  Time
>      0           .000000      D      1     0      42.000000     0
>     58       49844.00000      D      0     0        .000000     0
> Uncrunching matrix
>     58       49844.00000      D      0     0        .000000     0
> Optimal solution found
> Presolved problem has:    372 rows     666 cols    1637 non-zeros
> ?140 Warning: Basis lost - recovering
> 
>    Its         Obj Value      S   Ninf  Nneg        Sum Inf  Time
>      0       30800.00000      D      6     0        .000000     0
>      1       49844.00000      D      0     0        .000000     0
> Optimal solution found
> 
> Starting root cutting & heuristics
> 
>  Its Type    BestSoln    BestBound   Sols    Add    Del     Gap     GInf   Time
> +         49844.00000  49844.00000      1               .000000        0      0
>  *** Relative MIP gap less than MIPRELSTOP ***
>  *** Search completed ***     Time:     0 Nodes:     1
> Number of integer feasible solutions found is 1
> Best integer solution found is  49844.00000
> Best bound is  49844.00000
> Uncrunching matrix
> decrementInstanceCounter:: numInstances 1
> 
> 
>