Constraint Density Detector

Overview

ID	Full Name	Propagate	Finish	Postprocess
D	densemasterconss	✓

This detector adds all constraints that have at least two variable coefficients that are closer than \(1\) apart from another to the master constraints.

Algorithmic Details

• Iterate over all open constraints ( \(N\) many)
  • For each constraint, get the number of nonzeros ( \(n_{\text{nonzeros}}=\)getNVarsForCons()) and make a tuple of the two: \((n,c)\), with \(c\) the constraint and add it to the list l
• Sort the tuples in l in ascending order by the first element (the neighborhood, higher means more dense).
• Set the last index to be \(r_{max}*N\), with \(r_{max}\) being the parameter "maximal ratio" (by default \(0.2\))
• Iterate over all constraints
  • If the last index (i.e. by default the first \(20\%\) of the constraints, starting with the greatest number of nonzeros) is reached, stop.
  • If the difference in nonzeros between the current item l[i] and the next item l[i+1] is smaller than the default maximum difference index= \(1\), set i to be the maximum difference index, i.e. if there is a jump between two constraints in their number of nonzero entries, stop.
• Set all constraints up until the maximum difference index to be master constraints, i.e. at max the first \(20\%\) of the constraints with the highest and similar neighborhood size.

Theoretical Details

Parameters

enabled               flag to indicate whether detector <densemasterconss> is enabled [TRUE]
finishingenabled      flag to indicate whether detector <densemasterconss> is enabled for finishing of incomplete decompositions [FALSE]
freqcallround         frequency the detector gets called in detection loop ,ie it is called in round r if and only if minCallRound <= r <= maxCallRound AND  (r - minCallRound) mod freqCallRound == 0 <densemasterconss> [1]
maxcallround          maximum round the detector gets called in detection loop <densemasterconss> [0]
mincallround          minimum round the detector gets called in detection loop <densemasterconss> [0]
origenabled           flag to indicate whether detector <densemasterconss> is enabled for detecting in the original problem [TRUE]
origfreqcallround     frequency the detector gets called in detection loop,i.e., it is called in round r if and only if minCallRound <= r <= maxCallRound AND  (r - minCallRound) mod freqCallRound == 0 <densemasterconss> [1]
origmaxcallround      maximum round the detector gets called in detection loop <densemasterconss> [2147483647]
origmincallround      minimum round the detector gets called in detection loop <densemasterconss> [0]
overruleemphasis      flag to indicate whether emphasis settings for detector <densemasterconss> should be overruled by normal settings [FALSE]
postprocessingenabled flag to indicate whether detector <densemasterconss> is enabled for postprocessing of finished decompositions [FALSE]
priority              priority of detector <densemasterconss> [0]
skip                  flag to indicate whether detector <densemasterconss> should be skipped if others found decompositions [FALSE]
usefullrecall         flag to indicate whether detector <densemasterconss> should be called on descendants of the current partialdec [FALSE]

Links

• Documentation: dec_densemasterconss.cpp