[Cbc] copying a linear program

[Lou Hafer]

John,

	Several comments and observations (since I'm not sure just what you're
trying to accomplish).

  * Deleting a solver interface should free all resources that it
    acquired. That doesn't seem to happen, so there's probably a
    bug in OsiCbc.

  * OsiCbc is regarded as a mistake by most of the developers, myself
    included (hence the general lack of response  :-)  No one who likes
    to use it is willing to maintain it. If you need to solve MIPs, use
    Cbc directly. If you just want to solve continuous LPs, use some
    other OsiXXX. OsiClp, for example.

  * You say you want to copy a linear program. Do you want copies of the
    model, or copies of the model embedded in a solver interface? Not a
    question I can answer from what you've written.

							Lou


On 12/12/11 11:46 AM, John Perry wrote:
> Hi
> 
> My apologies if I've sent this to the wrong list; let me know if so. (I tried 
> Osi, but they didn't answer, so maybe that was the wrong place.)
> 
> I want to copy a linear program many times (several hundred). An examination 
> of the source code suggests that this is the right approach:
> 
> #include "include/coin/OsiCbcSolverInterface.hpp"
> 
> int main() {
>   OsiCbcSolverInterface * si = new OsiCbcSolverInterface(NULL);
>   OsiCbcSolverInterface * newsi;
>   
>   for (int i = 0; i < 13; i++) {
>     newsi = new OsiCbcSolverInterface(si);
>     delete si;
>     si = newsi;
>   }
>   
>   while (true) {}
> }
> 
> but even this empty linear program, copied only 13 times, causes exponential 
> memory consumption, to the tune of hundreds of megabytes.
> 
> Am I going about this the wrong way, or is it a bug?
> 
> regards
> john perry