org.jfree.data.statistics
Class BoxAndWhiskerCalculator

java.lang.Object
  extended byorg.jfree.data.statistics.BoxAndWhiskerCalculator

public class BoxAndWhiskerCalculator
extends java.lang.Object

A utility class that calculates the mean, median, quartiles Q1 and Q3, plus a list of outlier values...all from an arbitrary list of Number objects.


Constructor Summary
BoxAndWhiskerCalculator()
           
 
Method Summary
static BoxAndWhiskerItem calculateBoxAndWhiskerStatistics(java.util.List values)
          Calculates the statistics required for a BoxAndWhiskerItem.
static double calculateMean(java.util.List values)
          Returns the mean of a list of numbers.
static double calculateMedian(java.util.List values)
          Calculates the median for a list of values (Number objects) that are in ascending order.
static double calculateMedian(java.util.List values, int start, int end)
          Calculates the median for a sublist within a list of values (Number objects) that are in ascending order.
static double calculateQ1(java.util.List values)
          Calculates the first quartile for a list of numbers in ascending order.
static double calculateQ3(java.util.List values)
          Calculates the third quartile for a list of numbers in ascending order.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

BoxAndWhiskerCalculator

public BoxAndWhiskerCalculator()
Method Detail

calculateBoxAndWhiskerStatistics

public static BoxAndWhiskerItem calculateBoxAndWhiskerStatistics(java.util.List values)
Calculates the statistics required for a BoxAndWhiskerItem.

Any items in the list that are not instances of the Number class are ignored. Likewise, null values are ignored.

Parameters:
values - A list of numbers (a null list is not permitted).
Returns:
Box-and-whisker statistics.

calculateMean

public static double calculateMean(java.util.List values)
Returns the mean of a list of numbers.

Parameters:
values - a list of numbers.
Returns:
The mean.

calculateMedian

public static double calculateMedian(java.util.List values)
Calculates the median for a list of values (Number objects) that are in ascending order.

Parameters:
values - the values in ascending order.
Returns:
The median.

calculateMedian

public static double calculateMedian(java.util.List values,
                                     int start,
                                     int end)
Calculates the median for a sublist within a list of values (Number objects) that are in ascending order.

Parameters:
values - the values in ascending order.
start - the start index.
end - the end index.
Returns:
The median.

calculateQ1

public static double calculateQ1(java.util.List values)
Calculates the first quartile for a list of numbers in ascending order.

Parameters:
values - the numbers in ascending order.
Returns:
The first quartile.

calculateQ3

public static double calculateQ3(java.util.List values)
Calculates the third quartile for a list of numbers in ascending order.

Parameters:
values - the list of values.
Returns:
The third quartile.