#14195: Bad error management in the CPLEX interface
-----------------------------+----------------------------------------------
Reporter: ncohen | Owner: tbd
Type: defect | Status: new
Priority: major | Milestone: sage-5.8
Component: PLEASE CHANGE | Keywords:
Work issues: | Report Upstream: N/A
Reviewers: | Authors: Nathann Cohen
Merged in: | Dependencies:
Stopgaps: |
-----------------------------+----------------------------------------------
Helloooooooooooo !!!
Recently a test did not pass in `generic_graph.py` when using CPLEX. And I
got the same problem with a MILP I am work on, the two of them being
probably related by their common use of constants with many decimals.
{{{
**********************************************************************
File "/home/ncohen/.Sage/devel/sage-2/sage/graphs/generic_graph.py", line
5779:
sage: for i in range(20):
g = DiGraph()
g.allow_multiple_edges(False)
for u,v in
digraphs.RandomDirectedGNP(n,RealNumber('.2')).edges(labels = False):
g.add_edge(u,v,round(random(),Integer(5)))
for u,v in digraphs.Circuit(n).edges(labels = False):
if not g.has_edge(u,v):
g.add_edge(u,v,round(random(),Integer(5)))
v2 = g.traveling_salesman_problem(use_edge_labels = True)
v1 = g.traveling_salesman_problem(constraint_generation = False,
use_edge_labels = True)
c1 = sum(map(itemgetter(Integer(2)), v1.edges()))
c2 = sum(map(itemgetter(Integer(2)), v2.edges()))
if c1 != c2:
print "Error !",c1,c2
print "With constraint generation :",c2
print "Without constraint generation :",c1
break
Exception raised:
Traceback (most recent call last):
File "/home/ncohen/.Sage/local/bin/ncadoctest.py", line 1231, in
run_one_test
self.run_one_example(test, example, filename, compileflags)
File "/home/ncohen/.Sage/local/bin/sagedoctest.py", line 38, in
run_one_example
OrigDocTestRunner.run_one_example(self, test, example, filename,
compileflags)
File "/home/ncohen/.Sage/local/bin/ncadoctest.py", line 1172, in
run_one_example
compileflags, 1) in test.globs
File "<doctest __main__.example_74[24]>", line 9, in <module>
v2 = g.traveling_salesman_problem(use_edge_labels = True)
File "/home/ncohen/.Sage/local/lib/python/site-
packages/sage/graphs/generic_graph.py", line 5922, in
traveling_salesman_problem
raise ValueError("The given graph is not hamiltonian")
ValueError: The given graph is not hamiltonian
**********************************************************************
}}}
This is because the two variables that are currently used in Sage to
detect whether the problem is unfeasible or unbounded do not actually say
whether the PROBLEM has this property, but whether the "current solution"
has "been checked to satisfy" this property. Hence, a difference.
This patch uses the correct variable. And the doctest pass, and my MILP
which are NEVER unbounded are not unbounded either `:-P`
Nathann
http://pic.dhe.ibm.com/infocenter/cosinfoc/v12r5/index.jsp?topic=%2Filog.odms.cplex.help%2Frefcallablelibrary%2Fhtml%2Ffunctions%2FCPXsolninfo.html
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/14195>
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 unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.
