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Made long conversion conistent. Improved test coverage. JIRA: MATH-224. 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@791931 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Phil Steitz 2009-07-07 18:29:08 +00:00
parent ea0ea82673
commit 727570392c
2 changed files with 68 additions and 1 deletions
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2
src/java/org/apache/commons/math/stat/descriptive/AggregateSummaryStatistics.java
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@ -238,7 +238,7 @@ public class AggregateSummaryStatistics implements StatisticalSummary,
}
sum += current.getSum();
final double oldN = n;
final long curN = current.getN();
final double curN = current.getN();
n += curN;
final double meanDiff = current.getMean() - mean;
mean = sum / n;

67
src/test/org/apache/commons/math/stat/descriptive/AggregateSummaryStatisticsTest.java
View File

@ -77,6 +77,15 @@ public class AggregateSummaryStatisticsTest extends TestCase {
assertEquals("Wrong aggregate sum", 42.0, aggregate.getSum());
}
/**
* Test aggregate function by randomly generating a dataset of 10-100 values
* from [-100, 100], dividing it into 2-5 partitions, computing stats for each
* partition and comparing the result of aggregate(...) applied to the collection
* of per-partition SummaryStatistics with a single SummaryStatistics computed
* over the full sample.
*
* @throws Exception
*/
public void testAggregate() throws Exception {
// Generate a random sample and random partition
@ -108,6 +117,64 @@ public class AggregateSummaryStatisticsTest extends TestCase {
assertEquals(totalStats.getSummary(), aggregatedStats, 10E-12);
}
public void testAggregateDegenerate() throws Exception {
double[] totalSample = {1, 2, 3, 4, 5};
double[][] subSamples = {{1}, {2}, {3}, {4}, {5}};
// Compute combined stats directly
SummaryStatistics totalStats = new SummaryStatistics();
for (int i = 0; i < totalSample.length; i++) {
totalStats.addValue(totalSample[i]);
}
// Now compute subsample stats individually and aggregate
SummaryStatistics[] subSampleStats = new SummaryStatistics[5];
for (int i = 0; i < 5; i++) {
subSampleStats[i] = new SummaryStatistics();
}
Collection<SummaryStatistics> aggregate = new ArrayList<SummaryStatistics>();
for (int i = 0; i < 5; i++) {
for (int j = 0; j < subSamples[i].length; j++) {
subSampleStats[i].addValue(subSamples[i][j]);
}
aggregate.add(subSampleStats[i]);
}
// Compare values
StatisticalSummaryValues aggregatedStats = AggregateSummaryStatistics.aggregate(aggregate);
assertEquals(totalStats.getSummary(), aggregatedStats, 10E-12);
}
public void testAggregateSpecialValues() throws Exception {
double[] totalSample = {Double.POSITIVE_INFINITY, 2, 3, Double.NaN, 5};
double[][] subSamples = {{Double.POSITIVE_INFINITY, 2}, {3}, {Double.NaN}, {5}};
// Compute combined stats directly
SummaryStatistics totalStats = new SummaryStatistics();
for (int i = 0; i < totalSample.length; i++) {
totalStats.addValue(totalSample[i]);
}
// Now compute subsample stats individually and aggregate
SummaryStatistics[] subSampleStats = new SummaryStatistics[5];
for (int i = 0; i < 4; i++) {
subSampleStats[i] = new SummaryStatistics();
}
Collection<SummaryStatistics> aggregate = new ArrayList<SummaryStatistics>();
for (int i = 0; i < 4; i++) {
for (int j = 0; j < subSamples[i].length; j++) {
subSampleStats[i].addValue(subSamples[i][j]);
}
aggregate.add(subSampleStats[i]);
}
// Compare values
StatisticalSummaryValues aggregatedStats = AggregateSummaryStatistics.aggregate(aggregate);
assertEquals(totalStats.getSummary(), aggregatedStats, 10E-12);
}
/**
* Verifies that two StatisticalSummaryValues report the same values up
* to delta, with NaNs, infinities returned in the same spots. For max, min, n, values