Re: [Help-glpk] Basis read/write

[Andrew Makhorin]

> There #39;s a couple of features documented in 4.34 in the
> stand-alone solver section (Appendix D):

> (Options specific to simplex method)

> --bas filename read initial basis from filename in MPS format

> --wbas filename write nal basis to filename in MPS format

> Both are missing from the glpsol that I built on cygwin/Windows
> Vista, for versions 4.34 as well as 4.39.

> Now, documentation for 4.39 does NOT mention these features - so that
> #39;s at least consistent.

> I suspect this feature existed earlier on.  I think this could be a
> useful feature to keep, and I can quote my case here.

> I am essentially solving a large-ish LP whose parameters are
> generated by incrementing one parameter value.  And so, I dont expect
> too many changes in the solution for a large part of my increments,
> and hence using a final basis for one solution as an initial basis for
> the next could save a lot in time.

Options --bas and --wbas were temporarily removed from glpsol, since
they supported only fixed mps format. This made them useless in most
cases due to limitation of row/column name length to 8 chars (in
mathprog models the names produced by the translator are, as a rule,
longer).