SCIP 3.2.1

Features

several improvements of SCIP-Jack (STP application): extended presolving for STP variants, STP-specific branching rule, dual heuristic to generate initial LP relaxation SCIP-Jack is now competitive with problem specific state-of-the-art solvers on several well-known STP variants, e.g., the (rooted) prize-collecting Steiner tree problem.
new "force" parameter in (root)redcost propagator to run the propagator also with active pricers

Performance improvements

do not transfer solutions to original space, if SCIP is being freed
modified implication graph analysis of SOS1 constraint handler; a new component allows to deduce zero fixings of variables
made SOS1 constraint handler specific diving selection rule faster for the case that the SOS1 constraints do not overlap
improved disjunctive cuts by the 'monoidal cut strengthening' procedure of Balas and Jeroslow

Examples and applications

MultiObjective application renamed to PolySCIP; several improvements: better command line argument processing, overhaul of much of the source code, installation via CMake

Interface changes

made debug solution functionality thread safe (see debug.h for further information)

Deleted and changed API methods

add SCIPcomputeHyperplaneThreePoints to compute a hyperplane containing three given 3-dimensional points
SCIPsolveLinearProb now uses a 1-dimensional matrix representation

Command line interface

added interactive shell command 'display finitesolution' to print solution with infinite fixings removed, added reference to that method to 'display solution' output if there are infinite fixings
new interactive shell command "write history" to write the command line history (only when compiled with Readline)

Interfaces to external software

significantly improved Python interface to support user callbacks as well as linear and quadratic expressions

New parameters

"constraints/sos1/branchingrule" to decide whether to use neighborhood, bipartite, or SOS1 branching (this parameter replaces the old parameters "constraints/sos1/neighbranch", "constraints/sos1/bipbranch", and "constraints/sos1/sos1branch")
"constraints/sos1/depthimplanalysis" to limit the number of recursive calls of implication graph analysis
"constraints/sos1/perfimplanalysis" to perform an implication graph analysis to deduce variable fixings and additional SOS1 constraints (this parameter replaces the old parameter constraints/sos1/updateconflpresol)
"misc/transsolorig" for transfering transformed solutions to the original space (default: true)
"propagating/rootredcost/onlybinary" to propagate root reduced costs of binary variables only

Data structures

renamed MIP matrix structure to SCIP_MATRIX
changed the numeric values for PRESOLTIMING flags

Build system

Makefile

new target "dll" to build Windows dlls with MSVC
add new compiling flag OPENSOURCE to allow/forbid the usage of third party software

Fixed bugs

handle cutoffs in cons_indicator detected by infeasible inequalities
fixed wrong objective sense when copying the original problem
(root) reduced cost propagators are not run anymore when doing branch-and-price, since they may install upper bounds on variables which might interfere with the pricing (they may be enabled again by their force parameters)
fixed a bug in merge step of cliques during clean up phase; method did not correctly handle infeasibility in the case of multiple variable-negation pairs
fixed a previously untreated case in the linear cons simplification where coefficients only differ by slightly more than an epsilon
fixed too hard assertion in pseudoobj propagator
fixed inconsistency in knapsack constraint handler data during presolving
fixed bug in shiftandpropagate heuristic: the heuristic did not correctly handle intermediate, global bound changes of the selected variable after its tentative fixing led to a cutoff.
fixed a bug in shiftandpropagate where column positions after sorting are now correctly linked to their variables after sorting
fixed a bug in dive.c that occurred when lpsolvefreq was set to 1; after a cutoff, the solution values of the linked LP solution might have become invalid
fixed wrong check when computing cuts for factorable quadratic functions
fixed numerical problems in computation of cuts for bivariate functions in quadratic constraint handler
fixed bug in quadratic constraint handler when computing lifted-tangent inequalities
fixed bug in nonlinear constraint handler when replacing a violated nonlinear constraint leads to an infinite bound tightening of a single variable
do not analyse an infeasible LP for conflicts during diving mode when LHS/RHS of rows were changed
fixed some problem with reoptimization when the problems are infeasible or have been solved in presolving
fixed bug in SOS1 constraint handler with inconsistent data structure after restart
fixed wrong handling of negated variables in bound tightening procedure of SOS1 constraint handler
fixed bug in simple fixing heuristic of SOS1 constraint handler
fixed wrong handling of loose variables in OBBT
fixed freeing of hash for binary variables
fixed endless loop in knapsack constraint handler when continuous variables change their types to binary during presolving
squares of binary variables might not have been replaced by the binary variable itself in presolve, if the variable was originally general integer and only became binary during presolve (due to bound tightening)
fixed late change of type of slack variables in cons_indicator, if the bounds are not integral
fixed initsol and exitsol of cons_indicator, if problem has already been solved
fixed bug in parsing emphasis parameters which formerly led to completely wrong results
fixed bug in the computation of the Wilcoxon test
do not use the relative and absolute gap limit if no primal solution has been found so far
fixed two bugs in pseudoboolean constraint handler with wrong sorting of and constraints
use LPi infinity when reverting bound changes in conflict analysis
fixed bug in dive.c avoiding a check of constraints in the presence of indicator constraints
fixed bug in conflict.c with wrong reset of bounds used
fixed bug in heur_simplerounding in connection with relaxators
fixed bug in feaspump heuristic where last solution candidates were not updated correctly
fixed bug with transferring solutions to new runs (need to recompute objective before checking)
fixed bug in cons_indicator with changing type of slackvariable
fixed issue: constraints being parallel to objective function (after restart) sometimes led to wrongly stating infeasible
fixed issue with infinite values when checking cuts for redundancy
fixed bug during the computation of branching points for continuous variables which are almost fixed to +/- SCIPinfinity()
fixed library problems on Windows operating systems
fixed bug during coefficient tightening in varbound constraint handler
treated the case of integer variables as intermediate variables in the process of obtaining the active variable for a given binary variable
fixed bug with infinite shift values in heur_shifting
fixed potential memory leak in genvbound propagator

SCIP 3.2.0

Features

added reoptimization feature for optimization problems with changed objective function or tighter feasible region
improved clique and variable bound heuristics
new heuristic distribution diving that bases its score function on the changes regarding solution density
obbt propagator applies now additional separation and propagation in order to learn stronger and more bound tightenings
extended probing mode to allow separation and objective coefficient changes
variable histories can be transferred between sub-SCIPs solved by LNS heuristics and the component presolver and the main SCIP to reuse this information.
tighter reliability notions introduced for reliability branching, based on pseudo-cost relative errors and comparing candidates with the best pseudo-candidate using a 2-sample student-T test. These methods are used in disjunction with the existing reliability notion that uses a fixed number as reliability threshold for every variable before turning off strong-branching. This means, the classical method must be turned off by setting parameters minreliable and maxreliable to 0. The behavior is controlled through several parameters.
new distribution branching rule to base decisions on row activity (normal) distribution over domain space
new heuristic heur_indicator that tries to make partial solutions with indicator constraints feasible. It also tries to improve them (or external solutions) by a one-opt local search.
can now output information for BAK: Branch-and-bound Analysis Kit
the MPS reader can now read semi-integer variables, they are handled by creating bound disjunction constraints
the original problem can now be permuted directly after reading (if misc/permutationseed has value >gt;= 0)
added methods to compute strongly connected components with Tarjan's Algorithm
the MPS reader can now handle objective constants given as (the negation of) the RHS of the objective row
we can now upgrade quadratic constraints with one bilinear term to SOC constraints
we can also upgrade general quadratic constraints with a single negative eigenvalue to SOC constraints
new score in hybrid reliability pseudocost branching that prefers nonlinear variables when solving MINLPs
new heuristic (heur_bound) which fixes all integer variables to their lower/upper bounds and solves the remaining LP
new branching rule multaggr which allows to branch on general disjunctions defined by fractional multi-aggregated variables
Improved coordination of presolvers. There are three timings for presolvers now, FAST, MEDIUM and EXHAUSTIVE. Each presolving callback can specify one or more of these timings in which it will be called later. Within a presolving method, the current timing can be checked and the algorithms to be performed selected based on the timing. In one presolving round, first all presolving methods with timing FAST are called, sorted by priority. If they found enough reductions, a new round is started, otherwise, all presolving methods with timing MEDIUM are called. Again, with enough reductions, a new presolving round is started, too few reductions lead to running the EXHAUSTIVE presolvers. Similar to the delay concept used before, we are not neccessarily running all EXHAUSTIVE presolvers but stop as soon as one of them found enough reductions, starting a new presolving round immediately.
new branching rules for SOS1 constraints for branching on a neighborhood or a complete bipartite subgraph of the conflict graph. In addition to variable domain fixings, it is sometimes also possible to add complementarity constraints to the branching nodes. This results in a nonstatic conflict graph, which may change dynamically with every branching node.
modified diving heuristics to handle SOS1 constraints
improved separation procedure of SOS1 constraint handler, including bound (clique) cuts and implied bound cuts
new disjunctive cut separator for SOS1 constraints
new presolving components for SOS1 constraints, including bound tightening and clique extension
added method to propagate implications of SOS1 variables
convex quadratic contraints can now generate gradient cuts which are supporting to the feasible region
new edge-concave cut separator for quadratic constraints
SoPlex interface can now (re)store dual steepest edge weights
new branching rule nodereopt to reconstruct the tree after changing the objective function
new primal heuristic for reoptimization: ofins - objective function induced neighborhood heuristic
new heuristic for reoptimization which constructs solutions based in the changes between the objective function and the optimal solution before changing the objective function
extended expression parsing to support power, realpower and signpower operators; started support for user-defined operators in expression trees/graphs
possibility to set a soft time limit which becomes active only after the first primal solution was found
new presolver tworowbnd for improving variable bounds and detecting redundant constraints added
new presolver dualagg for aggregating single up-/downlocked variables by a binary variable added
new presolver implfree for aggregating implied free variables added
new presolver redvub which can detect redundant variable upper bound constraints added
new presolver stuffing for fixing of singleton continuous variables added
added matrix module for getting access to the internal mixed inter linear problem matrix
better handling of large values returned by the LP solver
added more checks to SCIP{alloc,realloc,duplicate}BufferArray() to handle overflows properly
moved assertions in comparison methods from scip.c to set.c
Plugins
- new plugin for reoptimizing a sequence of optimization problem that differ in the objective function, e.g., sequences arising from column generation
- new plugin "compr" for rearranging the search tree, currently this only works on the reoptimization tree
Statistic
- extended variable branching statistics in the interactive shell by sample variance of unit gains
- extended statistic output of interactive shell by more information on diving heuristic behavior

Performance improvements

improved treatment of nonlinearities in hybrid reliability pseudo cost branching
improved separation procedure of SOS1 constraint handler
improved separation procedure for convex quadratic constraints
added presolving levels (FAST, MEDIUM and EXHAUSTIVE) to allow better balancing of presolvers
zi rounding heuristic uses buffer data structures, thereby decreasing total memory usage of SCIP
adjusted (hard) diving heuristics to solve fewer LPs. LP's are resolved only if a parameter-defined percentage of the variable bounds changed through domain propagation or at a predefined frequency.
some of the diving heuristics additionally consider indicator variables and SOS1 variables as candidate variables and try to make these constraint types feasible before passing a rounded solution to SCIPtrySol()
improved vartype upgradability from continuous to implicit variables in cons_linear.c, depending on their objective coefficients
using sparsity information of the SoPlex LP
new presolving/propagation algorithm using the gcd for ranged rows and equations in cons_linear
improved propagation of SOS1 constraint handler using the information from a conflict

Examples and applications

two new applications for multi-objective optimization (PolySCIP) and the Steiner Tree Problem in Graphs
new application for solving Steiner tree problems: SCIP-Jack can handle both the classical Steiner tree problem in graphs and 10 of its variants

Interface changes

New and changed callbacks

new callback function SCIP_DECL_CONSGETDIVEBDCHGS to provide constraint handler method to suggest dive bound changes during the generic diving algorithm, see type_cons.h for details
new callback SCIP_DECL_DIVESETGETSCORE to implement scoring function to guide diving

Deleted and changed API methods

avoid potential comparisons of different infinity values by adjusting the LP solution value
SCIPincludeConshdlr has a new argument to provide a divebdchg-callback for the constraint handler to include
SCIPintervalSign(), SCIPintervalAbs(), SCIPintervalMax(), SCIPintervalMin(), SCIPexprgraphGetNodePolynomialMonomialCurvature(), and SCIPexprgraphTightenNodeBounds() need an infinity value to decide whether an interval is empty or not
SCIPgetFeasibilityQuadratic() and SCIPgetActivityQuadratic() returns now a SCIP_RETCODE and needs an additional SCIP_Real* to store the result
methods which support statistical tests in pub_misc.h, SCIPstudentTGetCriticalValue(), SCIPcomputeTwoSampleTTestValue() etc.
new enum SCIP_CONFIDENCE_LEVEL for different levels of confidence for statistical tests.
new struct SCIP_DIVESET that bundles options for SCIP's diving heuristics; all hard diving heuristics (those without 'obj' at the beginning) include diveset and implement only the scoring callback.
rename all file "*_vbc.?" to the more generic "*_visual.?"
rename SCIPdigraphGetSuccessorsDatas() ->gt; SCIPdigraphGetSuccessorsData()
SCIPdigraphSetNSuccessors() sets the number of successors of some digraph node to a given value
moved buffer memory handling to blockmemory/memory.?; remove files type_buffer.h, struct_buffer.h buffer.h buffer.c; removed functions SCIP*buffer*() from scip.? and replaced them by macros; redesigned buffer interface to be similar to block memory; added checks for strange sizes
renamed SCIPconshdlrGetPropTimingmask() to SCIPconshdlrGetPropTiming(), new method SCIPconshdlrSetPropTiming()
removed SCIPconshdlrIsPresolvingDelayed() and SCIPconshdlrWasPresolvingDelayed()
removed "delay(presol)" parameter from SCIPinclude{Conshdlr,Presol,Prop}() and added "(presol)timing" parameter
new parameter "presoltiming" for method SCIPpresolCons()
SCIPvarIsSOS1() returns whether some variable is involved in an SOS1 constraint
SCIPgetConflictgraphSOS1() gets conflict graph of SOS1 constraints
SCIPvarGetNodeSOS1() returns node of SOS1 variable in the conflict graph
SCIPnodeGetVarSOS1() returns SOS1 variable associated to some given node in the conflict graph
SCIPmakeSOS1sFeasible() based on solution values, fixes variables to zero to turn all SOS1 constraints feasible
SCIPsolveLinearProb() solves a linear problem of the form Ax=b for a regular square matrix A

New API functions

started support for user-defined operators in expression trees/graphs (see SCIPexprCreateUser()), interface will likely change again in future SCIP versions
new setter function SCIPsetConshdlrGetDiveBdChgs() in scip.h to set dive bound change callback for this constraint handler
new methods for mixed inter linear matrix access (see pub_matrix.h) added
added new sorting functions SCIPsortRealRealRealBoolBoolPtr(), SCIPsortDownRealRealRealBoolBoolPtr()
added new sorting functions SCIPsortIntIntIntReal(), SCIPsortDownIntIntIntReal(), SCIPsortRealIntInt(), SCIPsortDownRealIntInt()
SCIPaddDiveBoundChange() to add a diving bound change to the diving bound change storage of SCIP together with the information if this is a bound change for the preferred direction or not, to be used by constraint handlers inside the getDiveBdChgs-callback
SCIPwriteParam() to write a single parameter to a file
SCIPcheckParam{Bool,Char,...}() to check whether a parameter value is within the feasible domain
SCIPchgCoefLinear() and SCIPdelCoefLinear() to modify linear constraint during problem creation
SCIPchgLhsQuadratic(), SCIPchgRhsQuadratic(), SCIPchgLinearCoefQuadratic(), SCIPchgSquareCoefQuadratic(), and SCIPchgBilinCoefQuadratic() to modify quadratic constraints during problem creation
SCIPgetFeasibilityQuadratic() and SCIPgetActivityQuadratic() to get the feasibility and activity of a quadratic constraint in a given solution
SCIPcutGetLPActivityQuot() in pub_cutpool.h to get the potion of LP's where this cut was sharp in an optimal basis.
SCIPcreateDiveset() to add a diveset to a heuristic. Heuristics may have multiple divesets under different names
SCIPperformGenericDivingAlgorithm() that performs diving with periodic LP resolve according to the diveset argument.
SCIPcomputeArraysIntersection() to compute the set intersection of two ordered arrays
SCIPcomputeArraysSetminus() to compute the set difference of two ordered arrays
BMSallocClearBlockMemoryArray()/SCIPallocClearBlockMemoryArray() and BMSallocClearBufferMemoryArray(), SCIPallocClearBufferArray() to allocate arrays that are initialized to 0
SCIPpresolGetTiming(), SCIPpresolSetTiming(), SCIP{conshdlr,prop}GetPresolTiming(), and SCIP{conshdlr,prop}SetPresolTiming()
SCIPaddSquareLinearization(), SCIPaddSquareSecant(), SCIPaddBilinLinearization() and SCIPaddBilinMcCormick() in cons_quadratic.h to compute linear under- and overestimation for bilinear and quadratic terms
SCIPbuffermem() to get buffer memory;

Command line interface

extended variable branching statistics and statistic output in the interactive shell (see Statistic section)
submenu for setting "vbc" settings renamed to "visual"
at the end of a command line run the best solution can now be output in the orignal space

Interfaces to external software

in the AMPL interface, variable and constraint attributes (flags) can now be set via suffixes, where 0 (unset) stands for the default, 1 for TRUE and other values for FALSE; see SCIPcreateVar() and SCIPcreateCons() for their meaning; for variables, "initial" and "removable" are recognized; for constraints, "initial", "separate", "enforce", "check", "propagate", "dynamic" and "removable" are recognized
the AMPL interface now passes an initial guess, if specified, as a solution (that will be checked for feasibility) to SCIP

Changed parameters

rowrepswitch set to 2.0, so row representation is activated if LP has at least 2 times more rows than columns
rename parameter "vbc/filename" to "visual/vbcfilename"
rename parameter "vbc/realtime" to "visual/realtime"
rename parameter "vbc/dispsols" to "visual/dispsols"
one can now set emphasis parameters at the beginning of a settings file; it should start with "emphasis:" and the contain the emphasis string, e.g., "emphasis: feasibility" or "emphasis: heuristics off".

New parameters

added parameter to switch pseudo cost update in diving heuristics (enabled by default)
"branching/relpscost/confidencelevel" to set the confidence level to be used by statistical tests
"branching/relpscost/higherrortol" to define the highest reliability threshold for relative error based reliability
"branching/relpscost/lowerrortol" to define a lower reliability threshold for relative error based reliability
"branching/relpscost/nlscoreweight" for weight of nonlinear score when branching on MINLPs
"branching/relpscost/usedynamicconfidence" to use a dynamic confidence level based on the amount of strong-branching simplex-iterations compared to the overall simplex iterations (default is FALSE)
"branching/relpscost/usehyptestforreliability" to enable strong branching decisions based on a 2-sample student-T test of all prior pseudo-cost observations between the best pseudo-candidate and the candidate for which to decide whether strong-branching should be applied
"branching/relpscost/userelerrorreliability" to enable relative error based reliability
"branching/relpscost/skipbadinitcands" for skipping strong-branching candidates whose estimated gain is significantly worse than the one of the locally best (sb or pseudo) candidate
"constraints/linear/multaggrremove" to perform multi-aggregations in linear constraint handler only if the constraint can be removed afterwards
"constraints/linear/rangedrowpropagation" to disabled newly implemented propagtion algorithm for ranged rows and equations
"constraints/quadratic/advanced/interiorcomputation" to select the way of computing and interior point for gauge cuts
"constraints/quadratic/gaugecuts" to enable convex quadratics to generate gradients cuts which are supporting
"constraints/soc/generalsocupgrade" to allow general quadratics to be upgraded to soc
"constraints/SOS1/addcomps" to add local complementarity constraints to the branching nodes (can be used in combination with neighborhood or bipartite branching)
"constraints/SOS1/addbdsfeas" to define a minimal feasibility value for local bound (clique) inequalities in order to be added to the branching node
"constraints/SOS1/addcompsdepth" to define the maximal depth for adding complementarity constraints
"constraints/SOS1/addcompsfeas" to define a minimal feasibility value for local complementarity constraints in order to be added to the branching node
"constraints/SOS1/autocutsfromsos1" to automatically switch to separating bound cuts from SOS1 constraints if the SOS1 constraints do not overlap
"constraints/SOS1/autosos1branch" to switch to SOS1 branching if the SOS1 constraints do not overlap
"constraints/SOS1/conflictprop" to define whether to use conflict graph propagation
"constraints/SOS1/bipbranch" to branch on a complete bipartite subgraph of the conflict graph
"constraints/SOS1/boundcutsdepth" to define the node depth of separating bound (clique) cuts
"constraints/SOS1/boundcutsfreq" to define the frequency for separating bound (clique) cuts
"constraints/SOS1/boundcutsfromgraph" to define whether to separate bound (clique) inequalities from the conflict graph
"constraints/SOS1/boundcutsfromsos1" to define whether to separate bound (clique) inequalities from SOS1 constraints
"constraints/SOS1/fixnonzero": If neighborhood branching is used, then fix the branching variable (if positive in sign) to the value of the feasibility tolerance
"constraints/SOS1/implcutsdepth" to define the node depth of separating implied bound cuts
"constraints/SOS1/implcutsfreq" to define the frequency for separating implied bound cuts
"constraints/SOS1/implprop" to define whether to use implication graph propagation
"constraints/SOS1/maxaddcomps" to define the maximal number of complementarity constraints added per branching node
"constraints/SOS1/maxboundcuts" to define the maximal number of bound (clique) cuts separated per branching node
"constraints/SOS1/maxboundcutsroot" to define the maximal number of bound (clique) cuts separated per iteration in the root node
"constraints/SOS1/maximplcuts" to define the maximal number of implied bound cuts separated per branching node
"constraints/SOS1/maximplcutsroot" to define the maximal number of implied bound cuts separated per iteration in the root node
"constraints/SOS1/maxextensions" to define maximal number of extensions that will be computed for each SOS1 constraint in presolving
"constraints/SOS1/maxsosadjacency" to define that the adjacency matrix of the conflict graph is not created in presolving if the number of SOS1 variables is too large
"constraints/SOS1/maxtightenbds" to define the maximal number of bound tightening rounds per presolving round
"constraints/SOS1/neighbranch" to branch on a neighborhood of the conflict graph
"constraints/SOS1/nstrongiter" to define the maximal number LP iterations to perform for each strong branching round
"constraints/SOS1/nstrongrounds" to define the maximal number of strong branching rounds to perform for each node (only available for neighborhood and bipartite branching)
"constraints/SOS1/sos1branch" to branch on a single SOS1 constraint, i.e., a clique of the conflict graph
"constraints/SOS1/sosconsprop" to define whether to use SOS1 constraint propagation
"constraints/SOS1/strthenboundcuts" to define whether to strengthen bound (clique) cuts in case bound variables are available
"constraints/SOS1/updateconflpresol" to update the conflict graph during the presolving procedure
"display/allviols" to print all violated constraints of the best solution during checksol in the scip shell
"heur/indicator/improvesols" that turns on the improvement of external solutions by one-opt
"heuristics/∗diving/lpresolvedomchgquot" to determine the percentage of changed domains since previous LP to trigger an LP resolve [default: 0.15] (* stands for eight diving heuristics to support this feature)
"heuristics/∗diving/lpsolvefreq" to determine the frequency for resolving LP's during the execution of this heuristic [default: 1, use 0 for a dynamic setting based on the number of domain reductions] (* stands for eight diving heuristics to support this feature)
"heuristics/shiftandpropagate/binlocksfirst" to set if binaries without locks should be preferred in ordering
"heuristics/shiftandpropagate/maxcutoffquot" to select a maximum percentage of allowed cutoffs before stopping the heuristic (default is 0.0)
"heuristics/shiftandpropagate/selectbest" to trigger if shiftandpropagate should select the best candidate in every round? (set to FALSE for static order) (default is FALSE)
"limits/autororestart" for triggering an automatic restart after this many nodes, or -1 for no auto restart [default is -1]
"limits/softtime" to set a soft time limit (active only after first primal solution was found)
"misc/allowobjprop" to allow objective function propagation
"misc/allowdualreds" to allow dual reductions
"misc/outputorigsol" to control whether at the end of a command line run the solution should be output in the orignal space
"numerics/checkfeastolfac" to scale feasibility tolerance when checking the feasibility of best found solution after the solving process finished (e.g., checksol in scip shell)
"separating/cutselrestart" for cut selection during restart copy process ('a'ge, activity 'q'uotient) [default is 'a']
"separating/cutselsubscip" for cut selection for sub SCIPs ('a'ge, activity 'q'uotient) [default is 'a']
"separating/disjunctive/maxconsdelay" to delay separation of disjunctive cuts if number of SOS1 constraints is larger than predefined value
"separating/disjunctive/maxdepth" to define the node depth of separating disjunctive cuts
"separating/disjunctive/maxinvcuts" to define the maximal number of disjunctive cuts investigated per iteration in a branching node
"separating/disjunctive/maxinvcutsroot" to define the maximal number of disjunctive cuts investigated per iteration in the root node
"separating/disjunctive/maxrank" to define the maximal permissible rank of a disjunctive cut that could not be scaled to integral coefficients
"separating/disjunctive/maxrankintegral" to define the maximal permissible rank of a disjunctive cut that could be scaled to integral coefficients
"separating/disjunctive/maxrounds" to define the maximal number of separation rounds of disjunctive cuts in a branching node
"separating/disjunctive/maxweightrange" to define the maximal valid range of simplex tableau row weights

Testing

added scripts and targets for testing with xpress (see Makefile section)

Build system

Makefile

new parameter 'DELHEADERS' for 'uninstall'-target: scip headers are only removed when invoking 'make uninstall DELHEADERS=true'
added scripts check_xpress.awk, check_xpress.sh, evalcheck_xpress.sh and check_cluster_xpress.sh and target "testclusterxpress" and "testxpress"

Fixed bugs

fixed bug in primal.c and tree.c by using SCIPinfinity() as a cutoffbound to delete child nodes
fixed bug in cons_indicator with handling local bounds
fixed bug in cons_quadratic.c which leads to an overflow when SCIP allocates memory for a dense matrix
fixed bug in lp.c which leads to wrong primal and dual feasibility
fixed wrong comparison when executing branching rule for external branching candidates
fixed bug in cons_abspower.c: do not generate cuts with infinity right-hand-side anymore
fixed wrong handling of infinite activities and primal values in sepastore.c and lp.c
fixed assert in cons_soc.c: now soc with 1 lhs variable are allowed
fixed bug that led to an erroneous warning about the clock type
fixed setting of enforcement flag for constraints created by reformulation in nonlinear constraint handlers
fixed bug in heur_nlpdiving.c: wrong counting of fix variables
fixed bug in cons_quadratic.c: do not generate linearization cuts for disabled constraints
fix behavior of 'make install' which now sets symbolic links and short links to binaries and libraries
fix characterization of logic or constraints in SCIP's NLP relaxation
fix wrong handling of SCIP_NLPSOLSTAT_LOCALINFEASIBLE solution status in nlp.c
fix bug which lead to wrong global bound tightenings in prop_genvbounds.c
fix missing clean phase of bilinear terms with zero coefficient in cons_quadratic.c
fix handling of infinite intervals in SCIPintervalIsEmpty()
fix potentially tightening of LB/UB of a variable to +/- infinity in cons_quadratic
fix spatial branching on implicit integer variables
fixed bug in intervalarith.c: bivariate quadratic equations may have been solved wrongly if second variable is unbounded
fix wrong sorting of bilinear terms in cons_quadratic
fix wrong comparisons of values larger/less than +/- SCIPinfinity() in branch.c, lp.c and sol.c
fixed wrong assert in cons_indicator (slack variables might be replaced by active variables that have nonzero objective)
try to handle fixings of multi-aggregated variable in cons_sos1 presolving and avoid error
fix potential memory leak in method SCIPgetConsCopy()
fix potential memory leak in method detectRedundantConstraints() of the knapsack constraint handler
fix potential memory leak in SoPlex LP interfaces when setting invalid basis
fix call to random generator for Windows operating systems in misc.c
fix late creation of auxiliary LP in cons_nonlinear.c, which lead to a segmentation fault with lpi_spx2.cpp
fixed again a bug in backward propagation of linear expressions in expression graph
fixed problem with lpisrelax flag in probing mode when doing branch-and-price
fixed bug in pseudoboolean constraint handler about negated variables