Re: [Help-glpk] API (4.54 glpk.h) vs. Docs

[Andrew Makhorin]

> I would like to clear up some things about the API as described in 
> glpk.h (for version 4.54) versus what I can find in the (excellent) 
> documentation:
> 
> * In 'glp_iocp', the parameters 'use_sol' (GLP_ON/GLP_OFF?), 'save_sol', 
> and 'alien' are listed, but I have not found a description in the 
> documentation. Did I overlook something?

use_sol is a flag; if it is on, glp_intopt considers the current mip
solution stored in glp_prob as if it were found by heuristic. In
particular, glpsol option '--use filename' allows reading an initial mip
solution from filename and passing it to glp_intopt.
This feature is still experimental, so it is not documented.

save_sol is a character string; if it is not NULL, it should specify a
filename, to which glp_intopt saves every integer-feasible solution it
finds during the search. If the filename contains an asterisk '*',
the asterisk is substituted with a solution count '001', '002', etc.
Glpsol option '--save filename' allows using this feature.
This feature is also experimental and not documented.

alien is an internal flag; it is not available to the application.

> 
> * In 'glp_bfcp', the parameter 'upd_tol' is listed as "(not used)", but 
> it is (still?) listed in the documentation.

Currently this parameter is not used because of recent changes in the
basis factorization routines.

> 
> * 'glp_init_mpscp' and 'glp_init_cpxcp' are listed, but undocumented; I 
> guess because they do nothing as of yet?

These objects are intended to control the behavior of glp_read/write_mps
and glp_read/write_lp. However, currently they are not used and
therefore not documented.

> 
> * 'glp_main' is listed, but undocumented; I guess this is to write a 
> glpsol-like program?
> 
> 

It is the main function of glpsol. If necessary, the application may
call it to avoid running glpsol executable in a separate process.