SCIP support

[nathanncohen]

Based upon Harald Schilly's SPKG for SCIP, here is a patch to enable the use of this solver through the usual interface for LP.

Requires #8172 (though none of GLPK, CBC or CPLEX needs to be installed)

Nathann

CC: @malb @haraldschilly @sagetrac-r-gaia-cs

Component: linear programming

Reviewer: Vincent Delecroix

Issue created by migration from https://trac.sagemath.org/ticket/8672

[nathanncohen]

Description changed:

--- 
+++ 
@@ -1,3 +1,5 @@
 Based upon Harald Schilly's SPKG for SCIP, here is a patch to enable the use of this solver through the usual interface for LP.
 
+Requires #8172 (though none of GLPK, CBC or CPLEX needs to be installed)
+
 Nathann

[haraldschilly]

comment:2

wow, thank you!! just one thing, is it possible to enable verbose output if enabled? i don't know which parameter you have to set in Sage's MIP interface, but it is scip.solver(quiet=False) in scip.

[nathanncohen]

comment:3

Fixed ! The corresponding argument in sage is log=# in the solve method. 0 for no output, and integers to have progressdively more (only GLPk has different levels of output though, the others only understand 0/1 or none at all )

Nathann

[nathanncohen]

Attachment: trac_8672.patch.gz

[malb]

comment:4

Hi Nathann,

two small things:

• solve_scip has no documentation/doctests
• "the default solver is used (COIN if available, GLPK otherwise)" seems to be inaccurate since you also try SCIP whether it is available