[SCIP] SoPlex Status Code -7

[Marc Pfetsch]

Dear Waiming,

in SoPlex one should indeed always first include the columns, then the
rows. The run time overhead happens because of the internal data structures.

In your case, please reconsider whether it is at least possible to add
some columns up-front. From the times you indicate, it might be
advantageous to have a two-loop approach. In the first, you can count
the number of columns you need. Then you create the columns and then the
rows. Note that you can change properties of the columns later, so a
stand-in is possible.

Finally, you might consider solving the dual, where the roles of rows
and columns are flipped.

Hope this helps.

Best

Marc





On 12/05/2021 14:30, 朱外明 wrote:
> Hi,
> 
> I am using SoPlex 5.0.2 as a callable lib (coded in C++) to solve a LP
> problem. 
> 
> The tested instance is truely simple. However, SoPlex reports:
> 
> "Error: SoPlex returned with status -7." 
> 
> if I use  "row first column second" adding method, the outline code of
> which are as follows:
> 
> /*add rows*/
> for (int k = 0; k < n; k++){
> DSVector row(0);
> model.addRowReal(LPRow(row, soplex::LPRow::Type::LESS_EQUAL, rhs));
> }
> 
> /*add columns*/
> for (int k = 0; k < m; k++){
>         DSVector var(2);
> ...
>         model.addColReal(LPCol(ege->distance, var, infinity, 0.0));
> }
> 
> 
> SoPlex will works well if I code follow the "column first row second"
> method, in which the same instance can be solved in 0.01 seconds.
> 
> I also tried the function 'SetRealParam' to set the time limit:
> "model.setRealParam(SoPlex::TIMELIMIT, 10);" . But still failed.
> 
> I need to use the "row first column second" method as there is a special
> structure in my formulation. 
> 
> 
> I much appreciate if anyone who tell me what is the most possible reason
> or what should I do to make SoPlex works. 
> 
> Thanks a lot.
> 
> 
> Regards!
> 
> 
> -------------------------------------------------------------
> Waiming Zhu
> School of Management, Hefei University of Technology
> 
> 
> 
> 
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