svn commit: r1459876 - /commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java

[lu...@apache.org]

Author: luc
Date: Fri Mar 22 16:05:46 2013
New Revision: 1459876

URL: http://svn.apache.org/r1459876
Log:
Clarified origin of the class.

The original comments seemed to show the class was created from
Mixtools, which is GPL code. As per discussion on the JIRA issue
MATH-817 (see https://issues.apache.org/jira/browse/MATH-817), it
appears it is original work and NOT a derived work from Mixtools.
In fact, Mixtools was used mainly to verify the results and generate
some reference data (see the Junit test cases). Neither the code nor the
API from Mixtools were used.

Modified:
    commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java

Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java?rev=1459876&r1=1459875&r2=1459876&view=diff
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java (original)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java Fri Mar 22 16:05:46 2013
@@ -1,18 +1,18 @@
 /*
  * 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
+ * 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
+ *      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.
+ * 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.math3.distribution.fitting;
 
@@ -36,13 +36,18 @@ import org.apache.commons.math3.util.Mat
 import org.apache.commons.math3.util.Pair;
 
 /**
- * <a href="https://www.ee.washington.edu/techsite/papers/documents/UWEETR-2010-0002.pdf">
  * Expectation-Maximization</a> algorithm for fitting the parameters of
  * multivariate normal mixture model distributions.
  *
- * This implementation is based on
- * <a href="http://cran.r-project.org/web/packages/mixtools/index.html">CRAN Mixtools</a>
- *
+ * This implementation is pure original code based on <a
+ * href="https://www.ee.washington.edu/techsite/papers/documents/UWEETR-2010-0002.pdf">
+ * EM Demystified: An Expectation-Maximization Tutorial</a> by Yihua Chen and Maya R. Gupta,
+ * Department of Electrical Engineering, University of Washington, Seattle, WA 98195.
+ * It was verified using external tools like <a
+ * href="http://cran.r-project.org/web/packages/mixtools/index.html">CRAN Mixtools</a>
+ * (see the JUnit test cases) but it is <strong>not</strong> based on Mixtools code at all.
+ * The discussion of the origin of this class can be seen in the comments of the <a
+ * href="https://issues.apache.org/jira/browse/MATH-817">MATH-817</a> JIRA issue.
  * @version $Id$
  * @since 3.2
  */