Merge branch 'mt/branch_gomory' into 'master'

Branching via Cutting Plane Selection

See merge request integer/scip!3122

CHANGELOG

@@ -26,6 +26,8 @@ Features
 - added special presolving step for logicor and set covering/packing for constraints with two variables and one independent variable
 - increased the depth field of the tree structure from 16 to 30 bits and the max depth of the search tree from 65534 to 1073741822
 - added new cut selector plugin called cutsel_ensemble. Performs a superset of hybrid cutsel. Implements new filtering methods and scoring options.
+- added new branching rule based on Gomory mixed-integer cuts
+- added new branching score to the reliability pseudo-cost branching rule
 - added monoidal strengthening to intersection cut generation of nlhdlr_quadratic
 
 Performance improvements
@@ -41,6 +43,7 @@ Performance improvements
 - Use sassy/bliss as default symmetry computation package.
 - No longer linearize indicator constraints in undercover heuristic by default.
 - Deactivate pre-root heuristic zeroobj in undercover heuristic.
+- Added new branching score tiebreaker for reliability pseudo-cost branching rule
 - Try nearest bound if zero solution value is out of bounds in heuristic trivial.
 
 Examples and applications
@@ -97,6 +100,8 @@ Interface changes
   for managing a copy of the branch-and-bound tree for symmetry handling purposes.
 - SCIPdotWriteOpening(), SCIPdotWriteNode(), SCIPdotWriteArc(), SCIPdotWriteClosing()
 - SCIPincludeCutselEnsemble(), SCIPselectCutsEnsemble() to include cutsel_ensemble or use the selection algorithm
+- SCIPincludeBranchruleGomory() includes new gomory cut based branching rule
+- SCIPgetVarAvgGMIScore(), SCIPincVarGMISumScore(), SCIPgetVarLastGMIScore(), SCIPsetVarLastGMIScore() set historical values used by SCIP's default branching rule
 
 ### Command line interface
 
@@ -139,6 +144,8 @@ Interface changes
   that is at least as good as the given value
 - heuristics/undercover/{coverand,coverind,covernl} to control which nonlinearities to consider (by default only "and" and nonlinear constraints)
 - cutselection/ensemble/* all parameters for new ensemble cut selector
+- branching/relpscost/gmiavgeffweight specifies the weight in the relpscost branching score of the normalized  efficacy of all generated GMI cuts (for a variable)
+  branching/relpscost/gmilasteffweight specifies the weight in the elpscost branching score of the normalized efficacy of the last generated GMI cut (for a variable)
 - nlhdlr/quadratic/usemonoidal to enable monoidal strengthening when separating quadratics with intersection cuts
 - nlhdlr/quadratic/trackmore to collect more statistics for monoidal strengthening when separating quadratics with intersection cuts
 - nlhdlr/quadratic/useminrep to use the minimal representation to compute cut coefficients when separating quadratics with intersection cuts

Makefile

@@ -569,6 +569,7 @@ SCIPPLUGINLIBOBJ=	scip/benders_default.o \
 			scip/branch_cloud.o \
 			scip/branch_distribution.o \
 			scip/branch_fullstrong.o \
+			scip/branch_gomory.o \
 			scip/branch_inference.o \
 			scip/branch_leastinf.o \
 			scip/branch_lookahead.o \

src/CMakeLists.txt

@@ -35,6 +35,7 @@ set(scipsources
     scip/branch_cloud.c
     scip/branch_distribution.c
     scip/branch_fullstrong.c
+    scip/branch_gomory.c
     scip/branch_inference.c
     scip/branch_leastinf.c
     scip/branch_lookahead.c
@@ -483,6 +484,7 @@ set(scipheaders
     scip/branch_cloud.h
     scip/branch_distribution.h
     scip/branch_fullstrong.h
+    scip/branch_gomory.h
     scip/branch.h
     scip/branch_inference.h
     scip/branch_leastinf.h