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aherbert pushed a commit to branch master
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The following commit(s) were added to refs/heads/master by this push:
new 770882409 Allow fitting single column data
770882409 is described below
commit 7708824094a0213db07f09897686645437f580f8
Author: aherbert <aherb...@apache.org>
AuthorDate: Tue Mar 5 17:29:18 2024 +0000
Allow fitting single column data
---
...ariateNormalMixtureExpectationMaximization.java | 6 +--
...teNormalMixtureExpectationMaximizationTest.java | 48 ++++++++++++++++++++++
2 files changed, 51 insertions(+), 3 deletions(-)
diff --git
a/commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java
b/commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java
index ee5993039..8b51195ab 100644
---
a/commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java
+++
b/commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/distribution/fitting/MultivariateNormalMixtureExpectationMaximization.java
@@ -81,7 +81,7 @@ public class MultivariateNormalMixtureExpectationMaximization
{
* @throws DimensionMismatchException if rows of data have different
numbers
* of columns
* @throws NumberIsTooSmallException if the number of columns in the data
is
- * less than 2
+ * less than 1
*/
public MultivariateNormalMixtureExpectationMaximization(double[][] data)
throws NotStrictlyPositiveException,
@@ -99,9 +99,9 @@ public class MultivariateNormalMixtureExpectationMaximization
{
throw new DimensionMismatchException(data[i].length,
data[0].length);
}
- if (data[i].length < 2) {
+ if (data[i].length < 1) {
throw new
NumberIsTooSmallException(LocalizedFormats.NUMBER_TOO_SMALL,
- data[i].length, 2, true);
+ data[i].length, 1, true);
}
this.data[i] = Arrays.copyOf(data[i], data[i].length);
}
diff --git
a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/distribution/fitting/MultivariateNormalMixtureExpectationMaximizationTest.java
b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/distribution/fitting/MultivariateNormalMixtureExpectationMaximizationTest.java
index a2fe49684..7a1e84282 100644
---
a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/distribution/fitting/MultivariateNormalMixtureExpectationMaximizationTest.java
+++
b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/distribution/fitting/MultivariateNormalMixtureExpectationMaximizationTest.java
@@ -17,6 +17,7 @@
package org.apache.commons.math4.legacy.distribution.fitting;
import java.util.ArrayList;
+import java.util.Arrays;
import java.util.List;
import
org.apache.commons.math4.legacy.distribution.MixtureMultivariateNormalDistribution;
@@ -241,6 +242,53 @@ public class
MultivariateNormalMixtureExpectationMaximizationTest {
}
}
+ @Test
+ public void testFit1() {
+ // Test that the fit can be performed on data with a single dimension
+ // Use only the first column of the test data
+ final double[][] data = Arrays.stream(getTestSamples())
+ .map(x -> new double[] {x[0]}).toArray(double[][]::new);
+
+ // Fit the first column of test samples using Matlab R2023b (Update 6):
+ // GMModel = fitgmdist(X,2);
+
+ // NegativeLogLikelihood (CM code use the positive log-likehood
divided by the number of observations)
+ final double correctLogLikelihood = -2.512197016873482e+02 /
data.length;
+ // ComponentProportion
+ final double[] correctWeights = new double[] {0.240510201974078,
0.759489798025922};
+ // Since data has 1 dimension the means and covariances are single
values
+ // mu
+ final double[] correctMeans = new double[] {-1.736139126623031,
3.899886984922886};
+ // Sigma
+ final double[] correctCov = new double[] {1.371327786710623,
5.254286022455004};
+
+ MultivariateNormalMixtureExpectationMaximization fitter
+ = new MultivariateNormalMixtureExpectationMaximization(data);
+
+ MixtureMultivariateNormalDistribution initialMix
+ = MultivariateNormalMixtureExpectationMaximization.estimate(data,
2);
+ fitter.fit(initialMix);
+ MixtureMultivariateNormalDistribution fittedMix =
fitter.getFittedModel();
+ List<Pair<Double, MultivariateNormalDistribution>> components =
fittedMix.getComponents();
+
+ final double relError = 0.05;
+ Assert.assertEquals(correctLogLikelihood,
+ fitter.getLogLikelihood(),
+ Math.abs(correctLogLikelihood) * relError);
+
+ int i = 0;
+ for (Pair<Double, MultivariateNormalDistribution> component :
components) {
+ final double weight = component.getFirst();
+ final MultivariateNormalDistribution mvn = component.getSecond();
+ final double[] mean = mvn.getMeans();
+ final RealMatrix covMat = mvn.getCovariances();
+ Assert.assertEquals(correctWeights[i], weight, correctWeights[i] *
relError);
+ Assert.assertEquals(correctMeans[i], mean[0],
Math.abs(correctMeans[i]) * relError);
+ Assert.assertEquals(correctCov[i], covMat.getEntry(0, 0),
correctCov[i] * relError);
+ i++;
+ }
+ }
+
private double[][] getTestSamples() {
// generated using R Mixtools rmvnorm with mean vectors [-1.5, 2] and
// [4, 8.2]
