Re: R: [Help-glpk] A suggestion concerning a new option

[Antti Lehtila]

At 16:34 15/2/2010 +0200, Pietro Scionti wrote:
>________________________________________
>Da: Andrew Makhorin address@hidden
>Inviato: lunedì 15 febbraio 2010 14.05
>A: Pietro Scionti
>Cc: address@hidden
>Oggetto: Re: [Help-glpk] A suggestion concerning a new option
>
>>I could suggest the following. At first you solve lp relaxation and
>>save the optimal basic solution found in a file using --nomip and -w
>>options; you also can write the solution in a printable format using
>>-o option. Then you run glpsol with options --nointopt and --ini, in
>>which case it starts from the optimal basis previously saved. This
>>would allow you not to solve lp relaxation twice.
>
>
>I did think of something like that, but I erroneously tried the -r option and 
>got stuck immediately.
>This kind of solution is not what I hope for (because, say, if I let my 
>computer work during the night, in the morning I would find out it stayed idle 
>for hours because the lp solution was found in relatively little time, while 
>the mip part is always the busiest), but at least it saves me the time to 
>re-solve the lp, so thank you very much, Andrew.

Pietro: I think Andrew meant that when you let your computer work during the 
night, it would first solve the LP relaxation, and immediately thereafter the 
MIP problem, using the optimal basis of the LP relaxation as a starting point. 
Wouldn't that be enough work for one night?

Antti