commons-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From er...@apache.org
Subject [math] MATH-1270
Date Thu, 17 Sep 2015 22:15:50 GMT
Repository: commons-math
Updated Branches:
  refs/heads/master fb7e1e265 -> 924e1e906


MATH-1270

Visualization of quantization error.


Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo
Commit: http://git-wip-us.apache.org/repos/asf/commons-math/commit/924e1e90
Tree: http://git-wip-us.apache.org/repos/asf/commons-math/tree/924e1e90
Diff: http://git-wip-us.apache.org/repos/asf/commons-math/diff/924e1e90

Branch: refs/heads/master
Commit: 924e1e9064f90d958b4f57e9c9c0c543bd19dcfb
Parents: fb7e1e2
Author: Gilles <erans@apache.org>
Authored: Fri Sep 18 00:14:39 2015 +0200
Committer: Gilles <erans@apache.org>
Committed: Fri Sep 18 00:14:39 2015 +0200

----------------------------------------------------------------------
 src/changes/changes.xml                         |  2 +-
 .../neuralnet/twod/util/QuantizationError.java  | 76 ++++++++++++++++++++
 2 files changed, 77 insertions(+), 1 deletion(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/commons-math/blob/924e1e90/src/changes/changes.xml
----------------------------------------------------------------------
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 7f04ede..27a5ae1 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -60,7 +60,7 @@ If the output is not quite correct, check for invisible trailing spaces!
       <action dev="erans" type="add" issue="MATH-1270"> <!-- backported to 3.6 -->
         Various SOFM visualizations (in package "o.a.c.m.ml.neuralnet.twod.util"):
         Unified distance matrix, hit histogram, smoothed data histograms,
-        topographic error.
+        topographic error, quantization error.
       </action>
       <action dev="erans" type="add" issue="MATH-1268"> <!-- backported to 3.6 -->
         New interfaces to be implemented by algorithms that visualizes properties

http://git-wip-us.apache.org/repos/asf/commons-math/blob/924e1e90/src/main/java/org/apache/commons/math4/ml/neuralnet/twod/util/QuantizationError.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/commons/math4/ml/neuralnet/twod/util/QuantizationError.java
b/src/main/java/org/apache/commons/math4/ml/neuralnet/twod/util/QuantizationError.java
new file mode 100644
index 0000000..e7bb19e
--- /dev/null
+++ b/src/main/java/org/apache/commons/math4/ml/neuralnet/twod/util/QuantizationError.java
@@ -0,0 +1,76 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.math4.ml.neuralnet.twod.util;
+
+import org.apache.commons.math4.ml.neuralnet.MapUtils;
+import org.apache.commons.math4.ml.neuralnet.Neuron;
+import org.apache.commons.math4.ml.neuralnet.twod.NeuronSquareMesh2D;
+import org.apache.commons.math4.ml.distance.DistanceMeasure;
+
+/**
+ * Computes the quantization error histogram.
+ * Each bin will contain the average of the distances between samples
+ * mapped to the corresponding unit and the weight vector of that unit.
+ */
+public class QuantizationError implements MapDataVisualization {
+    /** Distance. */
+    private final DistanceMeasure distance;
+
+    /**
+     * @param distance Distance.
+     */
+    public QuantizationError(DistanceMeasure distance) {
+        this.distance = distance;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public double[][] computeImage(NeuronSquareMesh2D map,
+                                   Iterable<double[]> data) {
+        final int nR = map.getNumberOfRows();
+        final int nC = map.getNumberOfColumns();
+
+        final LocationFinder finder = new LocationFinder(map);
+
+        // Hit bins.
+        final int[][] hit = new int[nR][nC];
+        // Error bins.
+        final double[][] error = new double[nR][nC];
+
+        for (double[] sample : data) {
+            final Neuron best = MapUtils.findBest(sample, map, distance);
+
+            final LocationFinder.Location loc = finder.getLocation(best);
+            final int row = loc.getRow();
+            final int col = loc.getColumn();
+            hit[row][col] += 1;
+            error[row][col] += distance.compute(sample, best.getFeatures());
+        }
+
+        for (int r = 0; r < nR; r++) {
+            for (int c = 0; c < nC; c++) {
+                final int count = hit[r][c];
+                if (count != 0) {
+                    error[r][c] /= count;
+                }
+            }
+        }
+
+        return error;
+    }
+}


Mime
View raw message