#16714: Add a matrix of constraints in a LP
-------------------------------------+-------------------------------------
Reporter: ncohen | Owner:
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-6.4
Component: linear | Resolution:
programming | Merged in:
Keywords: | Reviewers:
Authors: Volker Braun | Work issues:
Report Upstream: N/A | Commit:
Branch: | 0090edc953f5930e0a10b0c981e99c317db6c27c
u/vbraun/add_a_matrix_of_constraints_in_a_lp| Stopgaps:
Dependencies: |
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Comment (by dimpase):
Replying to [comment:32 ncohen]:
> `add_linear_constraints` is supposed to work, and if not how you'd
envision it to work. Create empty rows and then mutate later? Or is the
constraint data just missing from the argspec? or what?
>
> I guess that it is meant to allocate space for new rows, before changing
the coefficient. As I said above I implemented this function only to
expose those that are available in the solvers, and they do the very same
thing (if not `less).
GUROBI does have [http://www.gurobi.com/documentation/5.6/reference-
manual/c_grbaddconstrs `GRBaddconstrs`] which a full thing, in the sense
you can specify a bunch of constraints, specified by a sparse matrix, at
once.
>
> GLPK: takes only a number of rows as an argument. Nothing else
> {{{
> glp_add_rows(self.lp, number)
> }}}
>
> Cplex: takes a number of rows and the corresponding upper/lower bound.
Plus names
>
> {{{
> CPXnewrows(self.env, self.lp, number, bound, sense, rng, c_names if
names else NULL) #
> }}}
there is
[http://web.njit.edu/all_topics/Prog_Lang_Docs/cplex80/doc/refman/html/addrows.html
`CPXaddrows`] in CPLEX, similar to the one in GUROBI.
--
Ticket URL: <http://trac.sagemath.org/ticket/16714#comment:39>
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