Commit 182c080b authored by Vlastislav Dohnal's avatar Vlastislav Dohnal
Browse files

Added a logging messages when node split is highly unbalanced 

* During the split a half of longest edges in spanning tree are tested for a balanced split.
parent f70bdb96

src/main/java/mtree/MTree.java

+7 −1
Original line number Diff line number Diff line
@@ -625,9 +625,13 @@ public class MTree extends Algorithm implements Serializable, SplittableAlgorith 
        // Splitting all objects into 2 sets representing objects of new nodes.

        objectList1 = Split.findAllObjectsInComponent(objectMap, le.getObject1());

        objectList2 = Split.findAllObjectsInComponent(objectMap, le.getObject2());

        if (objectList1 == null || objectList2 == null || Math.abs(objectList1.size() - objectList2.size()) > ((objectList1.size() + objectList2.size()) / 5))

        

        boolean unbalancedSplit = false;

        if (objectList1 == null || objectList2 == null || Math.abs(objectList1.size() - objectList2.size()) > ((objectList1.size() + objectList2.size()) / 5)) {

            System.err.println("Splitting a node " + n + " produces highly uneven partitions: " + ((objectList1 == null) ? -1 : objectList1.size())

                    + ":" + ((objectList2 == null) ? -1 : objectList2.size()));

            unbalancedSplit = true;

        }



        // Insertion of all edges into objectMap that do not connect the two

        // disjunctive sets of objects (objectList1 and objectList2).
@@ -668,6 +672,8 @@ public class MTree extends Algorithm implements Serializable, SplittableAlgorith 
                    r2 = Math.max(d2, r2);

                }

            }

            if (unbalancedSplit) 

                System.err.println("Splitting a node " + n + " produces highly uneven partitions - complete split: " + objectList1.size() + ":" + objectList2.size());

        }



        // Internal node entry pointing to the subtree n1 and n2, respectively.

src/main/java/mtree/utils/Split.java

+26 −13
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ import java.util.Arrays; 
import java.util.Comparator;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Set;
@@ -137,7 +138,11 @@ public class Split { 


        // Locating and removing edge which divides the spanning tree into 2

        // components.

        for (Edge e: spanSet) {

//        for (int i = 0; i < 2; i++) {

            Iterator<Edge> it = spanSet.iterator();

            for (int i = 0; i <= spanSet.size() / 2; i++) {     // Do not test all, but just half of longest edges

                Edge e = it.next();

                

                LocalAbstractObject o1 = e.getObject1(), o2 = e.getObject2();

                objectMap.get(o1).remove(e);

                objectMap.get(o2).remove(e);
@@ -152,6 +157,14 @@ public class Split { 
                objectMap.get(o1).add(e);

                objectMap.get(o2).add(e);

            }

            

//            if (min > objectMap.size() / 2) {

//                objectList1 = null;

//            } else {

//                break;

//            }

//        }

        

        return le;

    }