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Revert "Add FirstBestAdmissibleTabuSearch (#39)"
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This reverts commit e4db65a.
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@hdbeukel
hdbeukel committed Jun 14, 2017
1 parent 65a394f commit d96d7fc
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Showing 9 changed files with 44 additions and 749 deletions.
7 changes: 0 additions & 7 deletions .gitignore
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*.log
*.jar
*.zip
*.iml
.classpath
.project
**/.settings/**
**/.idea/**


/target/
Empty file modified .travis/add-sonatype-server.py
100644 → 100755
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1 change: 0 additions & 1 deletion pom.xml
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Expand Up @@ -7,7 +7,6 @@
<groupId>org.jamesframework</groupId>
<artifactId>james</artifactId>
<version>1.3-SNAPSHOT</version>
<relativePath>../james/james</relativePath>
</parent>
<!-- james core specifications -->
<artifactId>james-core</artifactId>
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171 changes: 33 additions & 138 deletions src/main/java/org/jamesframework/core/search/NeighbourhoodSearch.java
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import java.util.Arrays;
import org.jamesframework.core.search.status.SearchStatus;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.function.Predicate;
import org.jamesframework.core.exceptions.SearchException;
import org.jamesframework.core.problems.Problem;
Expand Down Expand Up @@ -332,143 +329,41 @@ && validate(move).passed()
protected final Move<? super SolutionType> getBestMove(Collection<? extends Move<? super SolutionType>> moves,
boolean requireImprovement,
Predicate<? super Move<? super SolutionType>>... filters){
return this.getBestMove(moves, requireImprovement, false, filters);
}

/**
* <p>
* Get the best valid move among a collection of possible moves. The best valid move is the FIRST one yielding the positive delta
* or the one that is non-tabu and yield the largest delta(see {@link #computeDelta(Evaluation, Evaluation)}) when being applied to the current solution.
* </p>
* <p>
* If <code>requireImprovement</code> is set to <code>true</code>, only moves that improve the current solution
* are considered, i.e. moves that yield a positive delta (unless the current solution is invalid, then all
* valid moves are improvements). Any number of additional filters can be specified so that moves are only
* considered if they pass through all filters. Each filter is a predicate that should return <code>true</code>
* if a given move is to be considered. If any filter returns <code>false</code> for a specific move, this
* move is discarded.
* </p>
* <p>
* Returns <code>null</code> if no move is found that satisfies all conditions.
* </p>
* <p>
* Note that all computed evaluations and validations are cached.
* Before returning the selected best move, if any, its evaluation and validity are cached
* again to maximize the probability that these values will remain available in the cache.
* </p>
*
* @param moves collection of possible moves
* @param requireImprovement if set to <code>true</code>, only improving moves are considered
* @param acceptFirstImprovement if set to <code>true</code>, return the first improvement move
* @param filters additional move filters
* @return first improving move or the best valid move, may be <code>null</code>
*/
@SafeVarargs
protected final Move<? super SolutionType> getBestMove(Collection<? extends Move<? super SolutionType>> moves,
boolean requireImprovement,
boolean acceptFirstImprovement,
Predicate<? super Move<? super SolutionType>>... filters){
// track first improvement move AND best valid move + corresponding evaluation, validation and delta
// Move<? super SolutionType> bestMove = null, firstImprovementMove = null;
// double bestMoveDelta = -Double.MAX_VALUE, curMoveDelta, firstImprovementMoveDelta = -Double.MAX_VALUE;
// Evaluation curMoveEvaluation, bestMoveEvaluation = null, firstImprovementMoveEvaluation = null;
// Validation curMoveValidation, bestMoveValidation = null, firstImprovementMoveValidation = null;
//
//
// // go through all moves
// for (Move<? super SolutionType> move : moves) {
// // check filters
// if(Arrays.stream(filters).allMatch(filter -> filter.test(move))){
// // validate move
// curMoveValidation = validate(move);
// if (curMoveValidation.passed()) {
// // evaluate move
// curMoveEvaluation = evaluate(move);
// // compute delta
// curMoveDelta = computeDelta(curMoveEvaluation, getCurrentSolutionEvaluation());
//
// // compare with current solution
// if(curMoveDelta > 0 // better than curSolution
// || !getCurrentSolutionValidation().passed()){
// firstImprovementMove = move;
// firstImprovementMoveDelta = curMoveDelta;
// firstImprovementMoveEvaluation = curMoveEvaluation;
// firstImprovementMoveValidation = curMoveValidation;
// break;
// }
//// if (curMoveDelta > bestMoveDelta // higher delta
//// && (!requireImprovement // ensure improvement, if required
//// || curMoveDelta > 0
//// || !getCurrentSolutionValidation().passed())) {
//// bestMove = move;
//// bestMoveDelta = curMoveDelta;
//// bestMoveEvaluation = curMoveEvaluation;
//// bestMoveValidation = curMoveValidation;
//// break;
//// }
// // compare with best move
// if (curMoveDelta > bestMoveDelta){ // higher delta
// bestMoveDelta = curMoveDelta;
// bestMove = move;
// bestMoveEvaluation = curMoveEvaluation;
// bestMoveValidation = curMoveValidation;
// }
//
//
// }
// }
// }
// // re-cache best move, if any
// if(bestMove != null && cache != null){
// cache.cacheMoveEvaluation(bestMove, bestMoveEvaluation);
// cache.cacheMoveValidation(bestMove, bestMoveValidation);
// }
// // re-cache best non-tabu move, if any
// if(firstImprovementMove != null && cache != null){
// cache.cacheMoveEvaluation(firstImprovementMove, firstImprovementMoveEvaluation);
// cache.cacheMoveValidation(firstImprovementMove, firstImprovementMoveValidation);
// }
// // If firstImprovementMove is not null, return firstImprovementMove.
// // Otherwise, return bestMove (which should be no better than currentSolution but be better than any other move)
//// if(firstImprovementMove != null)
//// return firstImprovementMove;
//// else
//// return bestMove;

// track the chosen move + corresponding evaluation, validation and delta
Move<? super SolutionType> chosenMove = null;
double chosenMoveDelta = -Double.MAX_VALUE, curMoveDelta = -Double.MAX_VALUE;
Evaluation chosenMoveEvaluation = null, curMoveEvaluation = null;
Validation chosenMoveValidation = null, curMoveValidation = null;
Iterator<? extends Move<? super SolutionType>> iteMove = moves.iterator();
while(iteMove.hasNext() &&
!(acceptFirstImprovement && // if acceptFirstImprovement=false, should check every move
chosenMoveDelta>0) ){ // if chosenMoveDelta<=0, should check every move
Move<? super SolutionType> curMove = iteMove.next();
if(Arrays.stream(filters).allMatch(filter -> filter.test(curMove))){
curMoveValidation = validate(curMove);
if(curMoveValidation.passed()){
curMoveEvaluation = evaluate(curMove);
curMoveDelta = computeDelta(curMoveEvaluation, getCurrentSolutionEvaluation());
if(curMoveDelta > chosenMoveDelta &&
(!requireImprovement // ensure improvement, if required
|| curMoveDelta > 0
|| !getCurrentSolutionValidation().passed())){
chosenMove = curMove;
chosenMoveDelta = curMoveDelta;
chosenMoveEvaluation = curMoveEvaluation;
chosenMoveValidation = curMoveValidation;
}
}
}
// track best valid move + corresponding evaluation, validation and delta
Move<? super SolutionType> bestMove = null;
double bestMoveDelta = -Double.MAX_VALUE, curMoveDelta;
Evaluation curMoveEvaluation, bestMoveEvaluation = null;
Validation curMoveValidation, bestMoveValidation = null;
// go through all moves
for (Move<? super SolutionType> move : moves) {
// check filters
if(Arrays.stream(filters).allMatch(filter -> filter.test(move))){
// validate move
curMoveValidation = validate(move);
if (curMoveValidation.passed()) {
// evaluate move
curMoveEvaluation = evaluate(move);
// compute delta
curMoveDelta = computeDelta(curMoveEvaluation, getCurrentSolutionEvaluation());
// compare with current best move
if (curMoveDelta > bestMoveDelta // higher delta
&& (!requireImprovement // ensure improvement, if required
|| curMoveDelta > 0
|| !getCurrentSolutionValidation().passed())) {
bestMove = move;
bestMoveDelta = curMoveDelta;
bestMoveEvaluation = curMoveEvaluation;
}
}
}
}
// re-cache the choseMove, if any
if(chosenMove != null && cache != null){
cache.cacheMoveEvaluation(chosenMove, chosenMoveEvaluation);
cache.cacheMoveValidation(chosenMove, chosenMoveValidation);
// re-cache best move, if any
if(bestMove != null && cache != null){
cache.cacheMoveEvaluation(bestMove, bestMoveEvaluation);
cache.cacheMoveValidation(bestMove, bestMoveValidation);
}

return chosenMove;
// return best move
return bestMove;
}

/**
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65 changes: 0 additions & 65 deletions src/main/java/org/jamesframework/core/search/algo/tabu/FirstBestAdmissibleTabuSearch.java
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3 changes: 1 addition & 2 deletions src/main/java/org/jamesframework/core/search/algo/tabu/TabuSearch.java
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Expand Up @@ -187,8 +187,7 @@ protected void searchStep() {
false,
// filter tabu moves (with aspiration criterion)
m -> !tabuMemory.isTabu(m, getCurrentSolution())
|| (validate(m).passed() &&
computeDelta(evaluate(m), getBestSolutionEvaluation()) > 0)
|| computeDelta(evaluate(m), getBestSolutionEvaluation()) > 0
);
if(move != null){
// accept move (also updates tabu memory by overriding move acceptance)
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