changelog.txt

SCIP-SDP version 4.3
====================

features:
- improved handling of Mosek enivronments for concurrent mode: free data of corresponding thread
- improved propagation of 3x3 minors by using that rows/columns are equal and do not need to check diagonal for t
- use current bounds in prepareLPData to detect fixed variables
- starting with SCIP 9, SCIP-SDP uses the callback functions of SCIP to compute the symmetry graph. The old code in
  src/symmetry is deprecated and will be removed in one of the next releases.
- renamed the file src/sdpi/config.h to src/sdpi/configf77.h

API changes:
- use const in SDPI and SDPI-solver interfaces

parameters:

fixed bugs:
- fidxed bug with calling tightenRowCoefs()
- fixed generation of primal matrix with Mosek
- fixed messages about removed zero coefficients in different CBF blocks

(c)make:
- change behavior of dependencies: now computed on the fly, while previously they were collected in a file;
  a make clean is needed whenever new files are added
- add parameter to choose "long long int" for Lapack (make ... LAPACKLONG=true, cmake .. -DLAPACKLONG=on; default: true/on)
- try to improve building with cmake on MacOS
- rework handling of SDPA (now adapted for SDPA 7.4.4)

SCIP-SDP version 4.2.0
======================

features:

- Revised the internal structure to store LP rows. They are now stored as common in LP-solvers, i.e., with an array that stores the
  beginning entries of each row. This saves memory and makes data handling easier.
- The tightening of rows in the relaxator has been moved to the SDPI.
- The SDPI-solvers now use a representation on which LP constraints have been removed.
- Implemented several functions to return (primal) solution data for SDPA (SCIPsdpiSolverGetPrimalSolutionMatrix, SCIPsdpiSolverGetPrimalLPSides)
- Refactored the code for warmstart information.
- Store number of LP rows in warmstart information and invalidate information if this does not match.
- Implemented cancelation and CMIR generation for conflict constraints.
- Add unit test for case in which all variables are fixed.
- Return primal solution if all variables are fixed.

API changes:
- SCIPsdpiLoadSDP() now takes information about integrality of variables.
- SCIPsdpiSolverLoadAndSolve(), SCIPsdpiSolverLoadAndSolveWithPenalty() now take parameter lpindchanges indicating whether the
  row has been removed or the number of rows removed before the current one.
- removed parameters success and sollength from SCIPrelaxSdpGetRelaxSol()
- renamed SCIPspdiGetSol() to SCIPsdpiGetDualSol() and remove parameter dualsollength
- renamed SCIPsdpiSolverGetSol() to SCIPsdpiSolverGetDualSol() and remove parameter dualsollength
- remove dualsollength from SCIPsdpiGetPreoptimalSol()
- createConsSavesdpsol() has a new parameter nlpcons

Parameters:
- removed paramter <relaxing/SDP/tightenrows>
- value 2 for <relaxing/SDP/warmstartprimaltype> has been removed (i.e., taking the dual, because this does not produce a feasible point)
- turn on conflict analysis by default

fixed bugs:
- fixed bug in the access to the primal solution matrix with DSDP
- fixed several bugs with computing conflict constraint
- The interface to DSDP now allocates memory once and reallocates it as needed, because DSDP needs it throughout the solution
  process and for accessing solutions.
- fix handling of interior point in warmstart if number of LP constraints has changed
- fixed bug in solving rounding problem with handling matrices
- fixed several memory issues with warmstart code

(c)make:
- turn off openblas by default, but turn it on for SDPA
- use cmake FindLAPACK

SCIP-SDP version 4.1.0
======================

features:
- Changed to the Apache 2.0 license.
- Add possibility to use ARPACK for eigenvalue computations with SDPs with one variable. For this just
  set ARPACK=true in the makefile. Note that using ARPACK is usually slower than using LAPACK.
- new propagation routine based on 3 by 3 minors
  (applied with parameter "constraints/SDP/prop3minors")
- can now create CMIR inequalities from eigenvector cuts
- revised and fixed checking routine for SDP rank 1 constraints
- add example for tighten matrices
- added check whether propagation of upper bounds can be applied in principle to save time
- allow to detect symmetries
  new files: sdpsymmetry.{c|h}, struct_sdpsymmetry.h, prop_sdpsymmetry.c in src/scipsdp/;
  also need a separate version of compute_sdpsymmetry.h,
  compute_symmetry_bliss.cpp, compute_symmetry_none.cpp,
  struct_sdpsymmetry.h, type_sdpsymmetry.h in src/symmetry.
- when reading distinguish between coefficients that are exactly 0 or nonzero but small

API changes:
- new function SCIPsdpiSolverGetPrimalSolutionMatrix() to access primal matrix solutions
- new function SCIPsdpiGetPrimalSolutionMatrix() to access primal matrix solutions
- new function SCIPsdpiSolverGetPrimalLPSides() to access primal solutions for LP sides
- new function SCIPsdpiGetPrimalLPSides() to access primal solutions for LP sides
- function SCIPsdpiSolverGetPrimalBoundVars() uses a success pointer instead of arraylength
- function SCIPsdpiGetPrimalBoundVars() uses a success pointer instead of arraylength
- new function SCIPsdpiGetSDPdata() to retrieve SDP data from SDPI
- new function SCIPsdpiHavePrimalSol() to determine whether a primal solution is available
- function SCIPsolveOneVarSDP() can now return a certificate of the status (certificatevector/certificatevalue)

parameters:
- new parameter <constraints/SDP/presollinconssparam> to decide how linear constraints are handled during presolving
- new parameter <constraints/SDP/prop3minors> to propagate 3 by 3 minors (default: TRUE)
- new parameter <constraints/SDP/nonconst3minors> to propagate 3 by 3 minors even if the diagonals are not constant (default: FALSE)
- new parameter <constraints/SDP/additionalstats> to show the number of propagations (default: FALSE)
- new parameter <constraints/SDP/generatecmir> to separate CMIR from eigenvalue cuts (default: TRUE)
- new parameter <reading/removesmallval> to remove small values when reading an instance in CBF or SDPA format (default: TRUE)
- new parameter <constraints/SDP/removesmallval> to remove small values in SDP constraints (default: FALSE)
- new parameters for symmetry handling:
  propagating/sdpsymmetry/maxgenerators, propagating/sdpsymmetry/checksymmetries, propagating/sdpsymmetry/displaynorbitvars,
  propagating/sdpsymmetry/doubleequations, propagating/sdpsymmetry/conssaddlp, propagating/sdpsymmetry/addsymresacks,
  propagating/sdpsymmetry/detectorbitopes, propagating/sdpsymmetry/detectsubgroups, propagating/sdpsymmetry/addweaksbcs,
  propagating/sdpsymmetry/addconsstiming, propagating/sdpsymmetry/ofsymcomptiming, propagating/sdpsymmetry/performpresolving,
  propagating/sdpsymmetry/recomputerestart, propagating/sdpsymmetry/compresssymmetries, propagating/sdpsymmetry/compressthreshold,
  propagating/sdpsymmetry/usecolumnsparsity, propagating/sdpsymmetry/maxnconsssubgroup, propagating/sdpsymmetry/usedynamicprop,
  propagating/sdpsymmetry/addstrongsbcs, propagating/sdpsymmetry/ssttiebreakrule, propagating/sdpsymmetry/sstleaderrule,
  propagating/sdpsymmetry/sstleadervartype, propagating/sdpsymmetry/addconflictcuts, propagating/sdpsymmetry/sstaddcuts,
  propagating/sdpsymmetry/sstmixedcomponents, propagating/sdpsymmetry/symfixnonbinaryvars, propagating/sdpsymmetry/onlybinarysymmetry,
  propagating/sdpsymmetry/preferlessrows.
- The main parameter for handling symmetries is propagating/sdpsymmetry/usesymmetry.

fixed bugs:
- fixed bug in tighten matrices (never ran previously)
- fixed output of statistics, i.e., avoid division by 0 in certain cases

(c)make:
- remove some unused files from cmake configuration
- shared libraries are built by default in cmake
- fixed make clean


SCIP-SDP version 4.0.0
======================

features:
- Separate cuts for all negative eigenvalues when solving with LP.
- new function SCIPlapackComputeEigenvectorsNegative() to compute only eigenvectors for negative eigenvalues
- allow to add SOC relaxation based on 2 by 2 minors.
- revised handling of LP-solving: use one function for separation and enforcement
- heur_sdpfracdiving and heur_sdprand now can also run for problems in which LPs are solved.
- new heuristic heur_sdpinnerlp that tries to find a diagonally dominant solution using an LP
- The display rows now switches from SDP to LP output depending on misc/solvesdps.
- add possibility to sparsify an eigenvector cut
- add possibility to add multiple sparse eigenvector cuts using the truncated power method (TPower)
- Add option to solve an SDP when solving LPs if there is an integer solution in enforcing. If the SDP is not feasible
  and not all integer variables are already fixed, add rounding step for all integer variables and solve SDP again.
- add possibility to tighten matrices if all matrices are positive semidefinite (turned off by default)
- add possibility to tighten bounds in presolving and propagation if all matrices are positive semidefinite (turned off by default)
- add propagation routine for upper bounds based on 2-by-2 minors
- The relaxator strengthened the rows of the LP corresponding to variable bounds before adding them to the current SDP.
  This has been extended by a full coefficient tightening procedure.
- use lexicographic sorting to sort matrix entries in SDPI
- Empty SDP constraints are now presolved and possibly removed.
- Streamlined the code at many places, in particular, in sdpi.c, sdpisolver_mosek.c, sdpisolver_sdpa.c, sdpisolver_dsdp.c.
  Here the data handling has been almost completely revised. Moreover, the data structures have been restructured to reduce
  reallocation. This reduces the memory footprint produced by empty blocks in memory.
- prop_sdpredcost has been revised, avoiding numerical troubles at several places.
- Revised the functions diagZeroImpl(), addTwoMinorLinConstraints().
- The SDPA reader has been rewritten in C.
- The SDPA reader supports a new optional section '*RANK1' that allows to specify rank-1-constraints. See 'sdpa-format.txt' for a description.
- added a check for infinity in the CBF and SDPA reader
- added more documentation to sdpi.c
- revised handling of problems in which all variables are fixed or the SDPI detects infeasibility
- SDPI now copies lower and upper bounds before possible strengthening.
- copy locking information to sub-SCIPSDPs (this avoids recomputing eigenvalues)
- reuse the mosek environment in each thread if possible
- sdpisolver_mosek now uses the SCIP message handler for output.
- use same time measurement within SDPI and SDPISOLVER as in SCIP
- new file scipsdpdef.h which contains the SCIPSDP version
- possibly update number of variables and consider added SDP constraints
- The number of threads used is now used by the SDPA interface.
- All SDP solvers now use the same default tolerances (feasibility and gap), and for Mosek the feasibility tolerance (<sdpsolverfeastol>)
  is tightened by 0.1.
- Remove table_sdpsolversuccess; its output has been added to table_relaxsdp.
- Heuristics <sdprand> now uses propagation to increase its success rate.
- Solve SDPs with one variable by using a semi-smooth Newton approach.
- Explicitly solve LPs with one variable.
- At several places, now block or buffer memory is used instead of malloc.
- The SDPI for Mosek allows to scale the problem (relaxing/SDP/scaleobj).
- SCIP-SDP redefines the default values of several parameters in SCIPSDPincludeDefaultPlugins(). Resetting parameters therefore
  returns to the default values for SCIP-SDP.
- Fixed several debug messages.
- Tuned compConstMatAfterFixings().
- All matrices in cons_sdp.c are enforced to be lower triangular.
- Keep SCIP variable order for SDPI.
- If cons_sdp.c finds a primal solution in enforcing directly add it without using heur_trysol.
- The documentation now uses MathJax to render math formulas.
- The LAPACK interface works with 32- and 64-bit library versions, since one cannot detect this at runtime.
  This also avoids problem with MATLAB replacing LAPACK by a 64-bit MKL.
- The output of the statistics has been extended and corrected at several places. In particular, more information is
  output for SDP solves.
- SCIP-SDP can now run concurrently. For this just call "concurrentopt" in the interactive shell.
- sdpisolver_dsdp now uses the objective values of the penalty formulation for a feasibility check.
- try to repair solution status in sdpisolver_mosek.c if Mosek stalled
- Heuristic sdprand fixes variables that are close to being integral to integral values. This avoids many
  numerical issues.
- new fractional rounding heuristic with intermediate propagation
- new presolving routine that adds linear inequalities based on variable bounds for 2 by 2 minors
  (applied with parameter "constraints/SDP/twominorvarbounds")

API changes:
- new functions SCIPconsSdpGetNVars() and SCIPconsSdpGetVars() in cons_sdp.c
- the function SCIPconsSdpCheckSdpCons() is now a static local function and no longer a global function
- SCIPcreateConsSdp() and SCIPcreateConsSdpRank1() have a new parameter removeduplicates to remove duplicates in matrices.
- Remove the functions SCIPsdpiSolverGetDefaultSdpiSolverFeastol() and SCIPsdpiSolverGetDefaultSdpiSolverGaptol(). The
  tolerances are now set by relax_sdp.c.
- new function SCIPsdpiGetMessagehdlr() in SDPI
- new functions SCIPsdpSolcheckerCheckAndGetViolDual() and SCIPsdpSolcheckerCheckAndGetViolPrimal() for checking solutions
- new functions SCIPsolveOneVarSDP() and SCIPsolveOneVarSDPDense() to solve SDPs with one variable by using a semi-smooth Newton approach

parameters:
- new parameter <constraints/SDP/separateonecut> to separate only one cut for the smallest eigenvalue (default: FALSE)
- new parameter <constraints/SDP/cutstopool> to add cuts to the pool (default: TRUE)
- new parameter <constraints/SDP/sparsifycut> to sparsify eigenvector cuts (default: FALSE)
- new parameter <constraints/SDP/sparsifyfactor> to determine target size for sparsifying eigenvector cuts (default: 0.1)
- new parameter <constraints/SDP/enforcesdp> to solve an SDP when solving LPs and there is an integral solution in enforcing (default: FALSE)
- new parameter <constraints/SDP/onlyfixedintssdp> to only solve SDP in enforcing if all integer variables are fixed (default: FALSE)
- new parameter <constraints/SDP/addsocrelax> to add SOC relaxation (default: FALSE)
- new parameter <constraints/SDP/usedimacsfeastol> for using a feasibility tolerance based on the DIMACS error for computing negative eigenvalues (default: FALSE)
- new parameter <constraints/SDP/generaterows> to determine if rows or constraints should be generated (default: TRUE)
- new parameter <constraints/SDP/propupperbounds> to turn on propagation of upper bounds (default: TRUE)
- new parameter <constraints/SDP/propubpresol> to turn on propagation of upper bounds in presolving (default: TRUE)
- new parameter <constraints/SDP/tightenboundscont> to only propagate upper bounds of continuous variables (default: FALSE)
- new parameter <constraints/SDP/tightenmatrices> to tighten (scale) matrices (default: FALSE)
- new parameter <constraints/SDP/tightenbounds> to tighten bounds based on eigenvalues (default: TRUE when solving SDPs, FALSE when solving LPs)
- new parameter <constraints/SDP/proptightenbounds> to turn on propagation of bound tightening (default: TRUE when solving SDPs, FALSE when solving LPs)
- new parameter <constraints/SDP/proptbprobing> to turn on propagation of bound tightening in probing (default: FALSE)
- new parameter <heuristics/sdpfracdiving/runforlp>, <heuristics/sdprand/runforlp> and <heuristics/sdpfracround/runforlp> to use heuristics starting from LP solution (default: FALSE)
- new parameter <misc/solvesdps> to choose between SDP (1) and LP (0) solving (default: 1)
- rename parameter <relaxing/SDP/tightenvb> to <relaxing/SDP/tightenrows>.
- Set default value for <relaxing/SDP/sdpsolverthreads> to 1, since this usually improves running time
  (set to -1 for an automatic choice, e.g., for larger SDP blocks).
- removed parameter <heuristics/sdprand/generalints>
- removed parameter <heuristics/sdprand/nrounds>
- new parameter <relaxing/SDP/usepresolving> to turn presolving of SDP-solver on (default: FALSE)
- new parameter <relaxing/SDP/scaleobj> to turn scaling of objective in SDP-solver on (default: FALSE)
- new parameter <constraints/SDP/twominorvarbounds> to add linear inequalities based on variable bounds for 2 by 2 minors during presolving (default: TRUE when solving SDPs, FALSE when solving LPs)
- new parameter <constraints/SDP/multiplesparsecuts> to add multiple sparse eigenvector cuts (default: FALSE)
- new parameter <constraints/SDP/maxnsparsecuts> to determine maximal number of sparse eigenvector cuts to add (default: 0)
- new parameter <constraints/SDP/recomputesparseev> to recompute sparse eigenvalues returned from TPower exactly (default: FALSE)
- new parameter <constraints/SDP/recomputeinitial> to recompute the initial vector for TPower every time (default: FALSE)
- new parameter <constraints/SDP/exacttrans> to exactly transform the matrix before calling TPower (default: FALSE)
- Set default value for <constraints/SDP/diaggezerocuts> to FALSE when solving SDPs, and to TRUE when solving LPs.
- Disable conflict analysis by default, i.e., set default value for <conflict/enable> to FALSE since this has no effect when solving SDPs and a negative influence when solving LPs.

fixed bugs:
- fixed the output of the line number when reading CBF files
- fixed one memory bug and one missing check in diagZeroImpl()
- fixed bug in multiaggrVar() with negative coefficients and locking
- fixed bug in multiaggrVar() and revised implementation
- fixed bug in fixAndAggrVars() if the multiaggregation reduces to 0 variables
- fixed bug in reading problems with indicator constraints
- fixed bug in presolving which sometimes avoided the addition of linear constraints
- fixed minor bug to allow copying of original problem
- fixed rpath for using Mosek
- fixed several minor issues in CBF reader
- disable oneopt heuristic when solving SDPs to avoid an infinite loop
- the SDPI is now more tolerant to unusual settings (no LP/SDP constraint, no constant part etc.)
- set objective value in relaxation even for infeasible or unbounded problems (this led to problems in prop_sdpredcost)
- At several places in cons_sdp.c treat the case of no SDP constraints or matrices.
- fixed several wrong return codes of status codes in SDPI
- treat unknown solution status in sdpisolver_dsdp.c
- fixed bug in relax_sdp with new variables that might be added
- avoid infinite loop with upgrading quadratic problems
- linear constraints added during presolving are not initial and are neither enforced nor checked
- fixed one bug when accessing solution statistics from Mosek for problems that have run into the timelimit in Mosek

(make)files:
- The makefile now produces various links to libscipsdp... and scipsdp...
- Fix cmake to work with Mosek 9.
- We do not need the following files anymore, since the SDPA reader has been rewritten: BlockMemoryAllocator.h, objreader_sdpa.cpp,
  objreader_sdpa.h, objreader_sdpaind.cpp, objreader_sdpaind.h, ScipStreamBuffer.cpp, ScipStreamBuffer.h
- Fixed linking of ubsan and clean/test targets in Makefile.
- SCIP-SDP can now be compiled with TPIs (for concurrent optimization).
- Avoid multiple symbols when linking LAPACK with CPLEX.
- weakened tolerances in cmprs.awk and check.awk


SCIP-SDP version 3.2.0
======================

interface:
- changed name of shell to "SCIP-SDP"
- increase output precision of CBF-files to 15 digits
- introduced function SCIPSDPincludeDefaultPlugins() that includes everything needed for SCIP-SDP
- SCIPconsSdpCheckSdpCons(): removed parameters checkintegrality, checklprows
- SCIPconsSdpComputeUbSparseSdpMatrixLength(): remove parameter scip

fixed bugs:
- fixed bug with statistics output when no SDPs were solved
- fixed minor bug in CBF-reader when reading DCOORD
- fixed bug with wrong matrix sizes in warmstarting code
- disabled the sdpobbt propagator if the SDP-relaxator is not available
- fixed memory leak in prop_sdpredcost with restarts
- only add presolving linear constraints once

features:
- add error messages to SDPA-format reader
- fix parsing of integer variables in SDPA-format
- add support for reading CBF-files in primal and mixed primal-dual form
- unify nomenclature, e.g., variable names, in CBF reader
- add more error messages to CBF reader
- add linenumbers to error messages in CBF reader
- the variable locks are now updated in presolving
- presolving techniques directly update bounds instead of adding constraints if possible
- unlocking variables is now faster (do not need to recompute eigenvalues in this case)
- adapted several code parts to newer SCIP versions and using new features
- add support for rank-1 constraints for psd variables and SDP-constraints by extending the SDP constraint handler, which now includes the following:
  - add one new parameter quadconsrank1 to ConshdlrData of cons_sdp
  - add three new variables rankone, maxevsubmat, addedquadcons to ConsData of cons_sdp
  - introduce function isMatrixRankOne() to check whether a matrix has rank 1
  - adapt locking mechanism to rank-1 constraints
  - introduce function enforceRankeOne() to enforce the rank-1 constraint for a given solution
  - for each constraint, if it should be rank one, all quadratic constraints given by the 2x2 principal minors are added in ConsInitSol,
    since a psd matrix has rank 1 if and only if all its 2x2 principal minors are zero.
  - add printing and parsing of rank-1 information in .cip-format as "rank1? 0/1"
  - SCIPconsSdpGetData(): add parameter rankone, maxevsubmat, addedquadcons
  - SCIPcreateConsSdp(): add parameter rankone
  - introduce function SCIPconsSdpShouldBeRankOne()
  - introduce function SCIPconsSdpGetMaxEVSubmat()
  - introduce function SCIPconsSdpAddedQuadCons()
  - introduce keywords PSDVARRANK1 and PSDCONRANK1 in reader_cbf.c for specifying psd variables and SDP-constraints with a rank-1 constraint
  - the new features are accessible via the virtual constraint handler SDPrank1 (SCIPcreateConsSdpRank1)
  - a new heuristic tries to construct rank1 solutions (parameter rank1approxheur; disabled by default)
- unify handling of LAPACK calls: there now is only one file "lapack_interface" instead of two (lpapack_sdpa, lapack_dsdp).
- two new presolving routines that add linear constraints, which are then propagated to possibly improve variable bounds
  (applied with parameters "constraints/SDP/twominorlinconss" and "constraints/SDP/twominorprodconss")
- add support for upgrading quadratic constraints to SDP rank1 constraints:
  - parameter upgradquadconss: turns upgrading on
  - in addition: parameter upgradekeepquad only adds SDP constraint as a relaxation
  - the upgrading is only performed if the number of variables and constraints is at most maxnvarsquadupgd

makefile:
- add project makefile in make/make.scipsdpproj
- reorganize main makefile to use make.scipsdpproj
- fix some minor issues in makefile concerning building with shared libraries
- use (pc)lint files from SCIP



SCIP-SDP version 3.1.2
======================

fixed bugs:
- fixed bug that could lead to segmentation faults after restarts when using the analytic center warmstarts
- sdpfracdiving only runs if the last SDP solve was outside of probing (before it could run directly after, e.g., sdp-obbt, which
  could lead to solutions with wrong objective values given to SCIP, since the objective values could still relate to those of the
  previous probing run)
- added additional tolerance factor (currently 1000) to sdp-obbt and only accept bound changes with improvement at least
  tolerance factor * gaptol (before smaller changes were also accepted, which, especially on integer variables, could lead
  to incorrect cutoffs or bound changes if these small differences were only caused by inaccuracy of the SDP solver)
- check for time limit during probing SDP within obbt-propagator to not return wrong cutoffs
- check for unboundedness in sdp-obbt problems
- explicitly handle unboundedness of the penalty problem
- fixed potential segmentation fault when reading cbf-files without any (SDP-)constraints or constant part
- fixed bug in cbf reader where equality constraints with right hand side zero were ignored
- return with reader error in optimized mode in CBF reader
- fixed bug with empty DCOORD section in CBF file reader
- make sure that matrix is in lower triangular form in CBF file reader

performance improvements:
- delay sdp-obbt if cutoffbound resulted from objective propagation only or the trivial heuristic, instead rerun after cutoffbound changed
  for the current node

interface:
- updated MOSEK interface to MOSEK 9

features:
- when reading CBF files, we now also allow that the conic parts appear multiple times, which are then aggregated
- allow to read CBF file version 2 (but do not support additional cones)
- CBF files: allow conic parts of constraints in different order
- CBF file: add more syntatic correctness checks


SCIP-SDP version 3.1.1
======================

fixed bugs:
- fixed potential segmentation fault if relaxator or redcost propagator were freed before initsol
- fixed potential segmentation fault caused by total number of nonzeros not being computed by SDP-constraint-parser for CIP format
- do not run sdp-obbt if relaxation solution is not valid
- changed relaxexit-callback to relaxexitsol for consistency and to avoid missing releaseVariables in UG

interface:
- add dat-s-ind reader to read instances in extended sdpa format with negative sign of variable index for indicator variables

parameters:
- added additional parameter "relaxing/SDP/peninfeasadjust" to increase numerical stability by only allowing cutoffs through the penalty
  formulation if the objective value of the feasilibity problem is at least this factor larger than the gap- and feasibility tolerance
  (default value is 10)
- changed restarts, cutagelimits and separating/maxrounds back to their SCIP defaults

Makefile:
- added experimental cmake support


SCIP-SDP version 3.1.0
======================

features:
- added possibility to warmstart SDPA and DSDP (deactivated by default) in several different ways, for details see parameter list in
  documentation and release report
- SCIP-SDP statistics are now included in SCIP statistics through new statistics table plugin type (old statistics output can still be
  activated via parameter relaxing/SDP/displaystatistics)
- compute and output constraint violations also for SDP constraints

performance improvements:
- accept solutions if MOSEK stalled but solutions are (almost) feasible (which is rechecked in the sdp interface later for the dual
  solution) and the duality gap is below the tolerance

parameters:
- changed default duality gap tolerance for MOSEK to 1e-5

core:
- adjustments for changes in SCIP relaxation solution enforcement


SCIP-SDP version 3.0.1
======================

fixed bugs:
- only declare problem infeasible in sdpredcost if lower bound exceeds upper bound by at least feastol (instead of epsilon)
- only change bounds in sdpredcost if they changed by more than feastol instead of epsilon (could lead to asserts for
  integer variables which are later rounded according to feastol)
- also compute objective values by hand for SDPA (like for MOSEK and DSDP), since returned objective sometimes does not match
  returned solution perfectly, which leads to errors inside SCIP

performance improvements:
- only create (and use) startsettings constraint handler for SDPA

core:
- disable dual propagators for reoptimization

makefile:
- added "make libscipsdp" to compile as library (needed, e.g., for parallelization via UG)


SCIP-SDP version 3.0.0
======================

fixed bugs:
- the SDPA interface incorrectly reused the settings of the last node instead of the parent node
- fixed fast/penalty/unsolved display columns to divide by number of interface calls instead of
  number of solver calls (which includes multiple calls for penalty formulation etc.)
- in SDPA interface if parent node used default settings, now continue with stable settings
  afterwards instead of directly moving to penalty formulation
- fixed memory leaks for fixed and (multi-)aggregated variables and in sdp-obbt
- input values are now checked against epsilon instead of feastol for detecting nonzeros
- only fix variables locally if lb-ub < epsilon instead of feastol
- feasibility is no longer checked against sdpsolverfeastol but instead against feastol everywhere
  (sdpsolverfeastol is now only used internally for the SDP-solver)
- immediately resolve SDP-relaxations if the required tolerance was not met by the solver
- fixed a problem which could lead to errors when the sdpredcost-propagator asked for information
  after the SDP-solver hit the SCIP-timelimit

features:
- readded "diagzeroimpl" cuts in presolving which enforce nonzero diagonal entries if a nonzero
  entry exists in the constant matrix for the corresponding row or column (under some prerequisites)

interface:
- added interface to MOSEK
- added reader for CBF format

parameters:
- The "diagzeroimpl" and diagonal >= 0 cuts of the SDP constraint handler can now be disabled through
  the parameters "constraints/SDP/diagzeroimplcuts" and "constraints/SDP/diaggezerocuts".
- "sdpsolverepsilon" has been renamed to "sdpsolvergaptol" to make the usage clearer
- The number of threads for MOSEK can be set via "relaxing/SDP/sdpsolverthreads"
- The maximum number of increases of the penaltyparameter and maximum number of decreases of the feasibility
  tolerance before declaring a problem unsolvable and continueing with the bound of the parent node can now
  be set via "relaxing/SDP/npenaltyincr"

core:
- adjusted SCIP-SDP to new enforelax callback in SCIP; this now allows to combine SCIP-SDP with other nonlinear
  constraints/constraint handlers

makefile:
- set links to mumps libraries instead of library folder
- All internal and external libraries are placed in lib/static and lib/shared, the include files are in lib/include.
- Current check scripts are now copied directly from the chosen SCIP directory.

SCIP-SDP version 2.1.0
======================

fixed bugs:
- current iterate is now correctly reset when changing parameters in SDPA
- parameters for SDPA are now set before inserting the problem so that they are also used for computing the initial point
- changed default lambda star parameter in SDPA to reduce aborts in infeasible subproblems
- changed default penalty parameter in DSDP to prevent cases where optimal solutions within the feasibility tolerance
  where cut off by DSDP
- fixed bug in reader that resulted in wrong computation of LP-row-indices when using multiple LP-blocks and could lead
  to segmentation faults
- infeasibility-status for presolving was not correctly reset after changing bounds
- check again for all variables fixed after local presolving, problems without variables may not be given to SDPA
- fixed some wrong asserts that used epsilon instead of feasibility tolerance
- one array in the SDPA interface was not properly resized after loading a second, bigger problem into the same SCIP shell
- number of SDP iterations now includes all solved SDPs, including those which were later resolved with different settings
  or the penalty formulation

features:
- added possibility to also check primal slater condition and output statistics in the end
- added diving heuristic for SDPs (disabled by default) [please note: This requires SCIP version 4.0 or higher and is 
  disabled for SCIP version 3.2.1 or lower]
- added randomized rounding heuristic for SDPs [please note: This requires SCIP version 4.0 or higher and is 
  disabled for SCIP version 3.2.1 or lower]
- added optimization-based bound tightening for SDPs (disabled by default) [please note: This requires SCIP version 4.0 
  or higher and is disabled for SCIP version 3.2.1 or lower]

performance improvements:
- in case of numerical problems in SDPA, child nodes are no longer tried to solve with fast settings in SDPA, but instead with
  whatever settings worked for the parent node (this can be controlled via parameter)

interface:
- added possibility to read and write in .cip format
- when using DSDP, the time limit is now checked after each iteration

parameters:
- penalty parameter to be used for numerically hard relaxations can now be changed by a parameter
- lambda star parameter for initial point in SDPA can now be changed by a parameter
- frequency of parameter resets in SDPA can be set by a parameter
- number of threads for SDPA/Openblas can now be changed via parameter if OpenMP is installed
- slatercheck is now an int parameter that also determines whether Slater results should be printed to console or
  only displayed as statistics in the end
- added parameter to control output of statistics after quitting SCIP-SDP

core:
- if an SDP relaxation cannot be solved, it is first checked for feasibility using an adjusted penalty formulation
  and only if the problem cannot be shown to be infeasible this way, a different penalty formulation is used to 
  solve the problem with the original objective function
- in the penalty formulation the primal bound added by the penalty parameter is now also checked to decide between
  increasing the penalty parameter or decreasing the feasibility tolerance, also the best lower bound computed by the
  penalty formulation is now used in SCIP even if the corresponding solution is not feasible in the original
  formulation

misc:
- percentage of unsolved SDP relaxations are now displayed in the shell; percentage of instances solved using the fastest
  settings (for SDPA, for DSDP this is the number of problems solved with the original formulation) and solved using the
  penalty formulation can also be displayed but are disabled by default
- statistics about number of SDP iterations, percentage of solved SDPs and (if enabled via parameter) percentage of 
  problems satisfying the Slater condition are now displayed after quitting SCIP-SDP


SCIP-SDP version 2.0.0
======================

fixed bugs:
- if DSDP does not converge but produces primal and dual feasible solutions, these are no longer accepted as optimal
- reader no longer crashes because of comment-lines between SDP/LP-block-lines
- value 0 in the last LP-block-line no longer causes an infinite loop
- non-numbers in the SDP/LP-block-lines and lines with more or less than five entries no longer cause infinite loops
  or get cut off or combined with others rows, but cause exits with meaningful error messages
- removed the diagDominant-cuts that are only correct for general MISDPs under some prerequisites

data structures:
- now uses arrays for the nonzeros instead of the SDP-cone class

features:
- dual/reduced cost fixing for SDPs
- added branching rules, as some of the SCIP branching rules only work on LP-solutions

performance improvements:

interface:
- added a more modular SDP-Interface and removed direct DSDP-references from the SCIPSDP-core-code
- added beta version of interface to SDPA

parameters:
- can now specify epsilon and feasibility tolerance for the SDP-solver specifically
- can specify whether an objective limit should be set for the SDP-solver
- can choose to display output of SDP-solver
- can choose to check slater condition in the dual problem ahead of solving the SDPs
- for a full list check the parameters tab in the documentation

core:
- transferred all code except for reader and SDPA-interface from C++ to C
- now uses the SCIP shell
- added SCIP 3.2.0 support
- bounds from SCIP are no longer transformed into LP-rows but are given to the SDP Solver (specifically DSDP, for SDPA 
  they still need to be transformed) as bounds

Makefile:
- creates extra directory sdpi for SDP-Interface
- SDP-solver is now specified via make option SDPS=...
- links are now set via console when calling make instead of the make.local file

misc:
- total and average SDP-iterations are displayed in the shell