Re: [Help-glpk] Interface to Coin OR Osi

[Andrew Makhorin]

Hi Xypron,

> Coin OR Osi offers an abstraction layer for different optimizers.

> GLPK can be accessed via Osi either as interpreter of GMPL models or
> as optimizer library.

> Currently the "official" API defined in doc/GLPK.pdf does not contain
> all functions necessary to use GLPK as interpreter only and to extract
> the model description. Hence OSI uses these undocumented functions:

> mpl_get_num_cols()
> mpl_get_num_rows()
> mpl_get_prob_name()
> mpl_get_obj_name()
> mpl_get_mat_row()
> mpl_get_row_kind()
> mpl_get_row_bnds()
> mpl_get_row_c0()
> mpl_get_row_name()
> mpl_get_col_name()
> mpl_get_col_bnds()
> mpl_get_col_bnds()
> mpl_get_col_kind()

> Will you add these function to the official API?

No, because glpk api already has all necessary routines to obtain
lp/mip problem data (glp_get_num_cols, glp_get_row_bnds, etc.).

> Currently usage of the undocumented functions requires to carefully
> watch the sequence of includes:
> #include "glpmpl.h"
> typedef MPL glp_tran;
> #define _GLP_TRAN
> #include "glpapi.h"

> This is a bit awkward. It would be preferable if the mpl_get-function
> where properly mapped to functions relying on the "abstract" glp_tran
> structure.

Using glpk.h and api routines automatically resolves this issue.


Andrew Makhorin