#10341: make MIP backend interface more Python-ic
----------------------------------------------+-----------------------------
Reporter: malb | Owner: ncohen
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-4.6.1
Component: linear programming | Keywords: LP, MIP
Author: Martin Albrecht, Nathann Cohen | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
----------------------------------------------+-----------------------------
Comment(by ncohen):
Oh, and I of course checked all the patches on CPLEX and Coin each time.
All tests do not pass, because of old bugs :
* Coin does not support names, so some doctests in mip.py fail because
of that
* for some reason the variable_min/max command on CPLEX variables that
are not bounded return a BIG NUMBER and not None when the variable is not
bounded (the doctest of a p.show() in mip.py fails because of that)
* There is a doctest in generic_graph that fails when one uses LP and
Coin to solve a max_flow problem on graphs whose edges are randomly
weighted. Coin sometimes answers 8.16540000001 instead of 8.1654 and the
tests is an equality.
In the end, the remaining bugs (and they have been there for quite a
while, but I did not really worry....) are all about displaying stuff. One
is about numerical noise on a very specific case (Coin + Flows. One also
has to know that by default Sage uses a Cython implementation of the Ford-
Fulkerson algorithm to compute a flow, and not the LP unless asked
otherwise -- I made the docstring of Graph.flow mention this noise).
Short of this, all tests pass in graph.py, digraph.py and
generic_graph.py. So all the methods there do not see the difference
between GLPK, Coin or CPLEX (except for the time spent testing the
docstrings) `;-)`
Would it be possible to address them in a future ticket ? And could I
please have your thoughts about removing all these names from the class ?
`:-)`
Nathann
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/10341#comment:36>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
