Author: dfilimon
Date: Tue May 21 08:38:48 2013
New Revision: 1484697
URL: http://svn.apache.org/r1484697
Log:
MAHOUT-1222: Fix total weight in FastProjectionSearch
Sometimes when removing a Vector that's in pendingAdditions, the wrong Vector
gets removed.
This happens because the closest Vector is removed rather than the one that's
equal to it.
Modified:
mahout/trunk/CHANGELOG
mahout/trunk/core/src/main/java/org/apache/mahout/math/neighborhood/FastProjectionSearch.java
Modified: mahout/trunk/CHANGELOG
URL:
http://svn.apache.org/viewvc/mahout/trunk/CHANGELOG?rev=1484697&r1=1484696&r2=1484697&view=diff
==============================================================================
--- mahout/trunk/CHANGELOG (original)
+++ mahout/trunk/CHANGELOG Tue May 21 08:38:48 2013
@@ -2,6 +2,8 @@ Mahout Change Log
Release 0.8 - unreleased
+__MAHOUT-1222: Fix total weight in FastProjectionSearch (dfilimon)
+
__MAHOUT-1219: Remove LSHSearcher from StreamingKMeansTest. It causes it to
sometimes fail (dfilimon)
MAHOUT-1221: SparseMatrix.viewRow is sometimes readonly. (Maysam Yabandeh
via smarthi)
Modified:
mahout/trunk/core/src/main/java/org/apache/mahout/math/neighborhood/FastProjectionSearch.java
URL:
http://svn.apache.org/viewvc/mahout/trunk/core/src/main/java/org/apache/mahout/math/neighborhood/FastProjectionSearch.java?rev=1484697&r1=1484696&r2=1484697&view=diff
==============================================================================
---
mahout/trunk/core/src/main/java/org/apache/mahout/math/neighborhood/FastProjectionSearch.java
(original)
+++
mahout/trunk/core/src/main/java/org/apache/mahout/math/neighborhood/FastProjectionSearch.java
Tue May 21 08:38:48 2013
@@ -52,11 +52,6 @@ public class FastProjectionSearch extend
// happened or not so we only do it once.
private boolean initialized = false;
- // Whether the iterator returned from the searcher was used to modify any of
the vectors. This
- // flag must be set manually by calling setDirty after said modification so
the internal
- // structures can be updated.
- private boolean dirty = false;
-
// Removing vectors from the searcher is done lazily to avoid the linear
time cost of removing
// elements from an array. This member keeps track of the number of removed
vectors (marked as
// "impossible" values in the array) so they can be removed when updating
the structure.
@@ -197,26 +192,25 @@ public class FastProjectionSearch extend
}
@Override
- public boolean remove(Vector v, double epsilon) {
- WeightedThing<Vector> closestPair = searchFirst(v, false);
- if (distanceMeasure.distance(closestPair.getValue(), v) > epsilon) {
+ public boolean remove(Vector vector, double epsilon) {
+ WeightedThing<Vector> closestPair = searchFirst(vector, false);
+ if (distanceMeasure.distance(closestPair.getValue(), vector) > epsilon) {
return false;
}
boolean isProjected = true;
- final Vector projection = basisMatrix.times(v);
+ final Vector projection = basisMatrix.times(vector);
for (int i = 0; i < basisMatrix.numRows(); ++i) {
List<WeightedThing<Vector>> currProjections = scalarProjections.get(i);
- int middle = Collections.binarySearch(currProjections,
- new WeightedThing<Vector>(projection.get(i)));
+ WeightedThing<Vector> searchedThing = new
WeightedThing<Vector>(projection.get(i));
+ int middle = Collections.binarySearch(currProjections, searchedThing);
if (middle < 0) {
isProjected = false;
break;
}
- double oldWeight = currProjections.get(middle).getWeight();
// Elements to be removed are kept in the sorted array until the next
reindex, but their inner vector
// is set to null.
- scalarProjections.get(i).set(middle, new
WeightedThing<Vector>(oldWeight));
+ scalarProjections.get(i).set(middle, searchedThing);
}
if (isProjected) {
++numPendingRemovals;
@@ -224,7 +218,7 @@ public class FastProjectionSearch extend
}
for (int i = 0; i < pendingAdditions.size(); ++i) {
- if (distanceMeasure.distance(v, pendingAdditions.get(i)) < epsilon) {
+ if (pendingAdditions.get(i).equals(vector)) {
pendingAdditions.remove(i);
break;
}
@@ -234,8 +228,8 @@ public class FastProjectionSearch extend
private void reindex(boolean force) {
int numProjected = scalarProjections.get(0).size();
- if (force || dirty || pendingAdditions.size() > ADDITION_THRESHOLD *
numProjected ||
- numPendingRemovals > REMOVAL_THRESHOLD * numProjected) {
+ if (force || pendingAdditions.size() > ADDITION_THRESHOLD * numProjected
+ || numPendingRemovals > REMOVAL_THRESHOLD * numProjected) {
// We only need to copy the first list because when iterating we use
only that list for the Vector
// references.
@@ -285,7 +279,6 @@ public class FastProjectionSearch extend
scalarProjections.get(i).clear();
}
numPendingRemovals = 0;
- dirty = false;
}
/**
@@ -298,30 +291,20 @@ public class FastProjectionSearch extend
public Iterator<Vector> iterator() {
reindex(true);
return new AbstractIterator<Vector>() {
- Iterator<WeightedThing<Vector>> data =
scalarProjections.get(0).iterator();
- @Override
- protected Vector computeNext() {
- WeightedThing<Vector> next;
- do {
- if (!data.hasNext()) {
- return endOfData();
- }
- next = data.next();
- if (next.getValue() != null) {
- return next.getValue();
- }
- } while (true);
+ Iterator<WeightedThing<Vector>> data =
scalarProjections.get(0).iterator();
+ @Override
+ protected Vector computeNext() {
+ WeightedThing<Vector> next;
+ do {
+ if (!data.hasNext()) {
+ return endOfData();
}
- };
- }
-
- /**
- * When modifying an element of the searcher through the iterator,
- * the user MUST CALL setDirty() to update the internal data structures.
Otherwise,
- * the internal order of the vectors will change and future results might be
wrong.
- */
- @SuppressWarnings("unused")
- public void setDirty() {
- dirty = true;
+ next = data.next();
+ if (next.getValue() != null) {
+ return next.getValue();
+ }
+ } while (true);
+ }
+ };
}
}
