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Improved javadoc. 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1134852 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Phil Steitz 2011-06-12 01:25:22 +00:00
parent e84687da98
commit 7d738dc352
1 changed files with 9 additions and 11 deletions
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20
src/main/java/org/apache/commons/math/stat/descriptive/rank/Percentile.java
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@ -61,18 +61,16 @@ import org.apache.commons.math.util.MathUtils;
* <p>
* Since percentile estimation usually involves interpolation between array
* elements, arrays containing <code>NaN</code> or infinite values will often
* result in <code>NaN<code> or infinite values returned.</p>
* result in <code>NaN</code> or infinite values returned.</p>
* <p>
* Since 2.2, Percentile implementation uses only selection instead of complete
* sorting and caches selection algorithm state between calls to the various
* {@code evaluate} methods when several percentiles are to be computed on the same data.
* This greatly improves efficiency, both for single percentile and multiple
* percentiles computations. However, it also induces a need to be sure the data
* at one call to {@code evaluate} is the same as the data with the cached algorithm
* state from the previous calls. Percentile does this by checking the array reference
* itself and a checksum of its content by default. If the user already knows he calls
* {@code evaluate} on an immutable array, he can save the checking time by calling the
* {@code evaluate} methods that do <em>not</em>
* Since 2.2, Percentile uses only selection instead of complete sorting
* and caches selection algorithm state between calls to the various
* {@code evaluate} methods. This greatly improves efficiency, both for a single
* percentile and multiple percentile computations. To maximize performance when
* multiple percentiles are computed based on the same data, users should set the
* data array once using either one of the {@link #evaluate(double[], double)} or
* {@link #setData(double[])} methods and thereafter {@link #evaluate(double)}
* with just the percentile provided.
* </p>
* <p>
* <strong>Note that this implementation is not synchronized.</strong> If