#18764: Add glp_exact to Sage's GLPK bindings
-------------------------------------+-------------------------------------
Reporter: mkoeppe | Owner:
Type: enhancement | Status: needs_review
Priority: minor | Milestone: sage-6.8
Component: numerical | Resolution:
Keywords: lp | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
u/mkoeppe/add_glp_exact_to_sage_s_glpk_bindings|
1ec429b9715686740a905465a7d1f6a0def5f899
Dependencies: | Stopgaps:
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Changes (by mkoeppe):
* status: new => needs_review
* commit: => 1ec429b9715686740a905465a7d1f6a0def5f899
Old description:
> The function glp_exact provides access to an implementation of the
> simplex method in exact rational arithmetic (using GMP).
>
> (The only access to data is via double-precision floats, however. It
> reconstructs rationals from doubles and provides results as doubles using
> the standard API functions of GLPK. Direct access, using GMP rationals,
> would be possible through the header file glpssx.h, which is not a public
> header as of GLPK 4.55; see http://lists.gnu.org/archive/html/help-
> glpk/2007-10/msg00031.html http://lists.gnu.org/archive/html/help-
> glpk/2008-06/msg00006.html http://lists.gnu.org/archive/html/help-
> glpk/2013-11/msg00019.html)
>
> (On the Sage side, one could reconstruct the rational solution via
> #18735.)
New description:
The function glp_exact provides access to an implementation of the simplex
method in exact rational arithmetic (using GMP).
The only access to data is via double-precision floats, however. It
reconstructs rationals from doubles and provides results as doubles using
the standard API functions of GLPK.
On the Sage side, since the combinatorial basis information is available
via get_col_stat, get_row_stat, one could then reconstruct the rational
solution. See #18735.
(Direct access, using GMP rationals, would be possible through the header
file glpssx.h; see ticket #18765.)
--
Comment:
Needs review.
----
New commits:
||[http://git.sagemath.org/sage.git/commit/?id=1ec429b9715686740a905465a7d1f6a0def5f899
1ec429b]||{{{Have solve call glp_exact if requested by solver parameter
simplex_or_intopt}}}||
--
Ticket URL: <http://trac.sagemath.org/ticket/18764#comment:4>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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