| java.lang.Object
 org.apache.commons.math.stat.descriptive.DescriptiveStatistics
All known Subclasses: org.apache.commons.math.stat.descriptive.DescriptiveStatisticsImpl, org.apache.commons.math.stat.descriptive.ListUnivariateImpl,
| DescriptiveStatistics | | abstract public class DescriptiveStatistics implements StatisticalSummary,Serializable(Code) | | Abstract factory class for univariate statistical summaries.
version:
$Revision: 348519 $ $Date: 2005-11-23 12:12:18 -0700 (Wed, 23 Nov 2005) $ |
| Field Summary | |
| final public static int | INFINITE_WINDOW
This constant signals that a Univariate implementation
takes into account the contributions of an infinite number of
elements. |
| Method Summary | |
| abstract public void | addValue(double v)
| | abstract public double | apply(UnivariateStatistic stat)
Apply the given statistic to the data associated with this set of statistics. | | abstract public void | clear()
| | abstract public double | getElement(int index)
| | public double | getGeometricMean()
| | public double | getKurtosis()
Returns the Kurtosis of the available values. | | public double | getMax()
| | public double | getMean()
| | public double | getMin()
| | abstract public long | getN()
| | public double | getPercentile(double p)
Returns an estimate for the pth percentile of the stored values. | | public double | getSkewness()
Returns the skewness of the available values. | | public double[] | getSortedValues()
Returns the current set of values in an array of double primitives,
sorted in ascending order. | | public double | getStandardDeviation()
Returns the standard deviation of the available values.
The standard deviation, Double.NaN if no values have been added or 0.0 for a single value set. | | public double | getSum()
Returns the sum of the values that have been added to Univariate. | | public double | getSumsq()
Returns the sum of the squares of the available values. | | abstract public double[] | getValues()
Returns the current set of values in an array of double primitives. | | public double | getVariance()
Returns the variance of the available values.
The variance, Double.NaN if no values have been added or 0.0 for a single value set. | | abstract public int | getWindowSize()
Univariate has the ability to return only measures for the
last N elements added to the set of values. | | public static DescriptiveStatistics | newInstance(Class cls)
Create an instance of a DescriptiveStatistics
Parameters:
cls - the type of DescriptiveStatistics object tocreate. | | public static DescriptiveStatistics | newInstance()
Create an instance of a DescriptiveStatistics
a new factory. | | abstract public void | setWindowSize(int windowSize)
WindowSize controls the number of values which contribute
to the values returned by Univariate. | | public String | toString()
Generates a text report displaying univariate statistics from values
that have been added. |
| INFINITE_WINDOW | | final public static int INFINITE_WINDOW(Code) | | This constant signals that a Univariate implementation
takes into account the contributions of an infinite number of
elements. In other words, if getWindow returns this
constant, there is, in effect, no "window".
|
| addValue | | abstract public void addValue(double v)(Code) | | Adds the value to the set of numbers
Parameters:
v - the value to be added |
| apply | | abstract public double apply(UnivariateStatistic stat)(Code) | | Apply the given statistic to the data associated with this set of statistics.
Parameters:
stat - the statistic to apply the computed value of the statistic. |
| clear | | abstract public void clear()(Code) | | Resets all statistics and storage
|
| getElement | | abstract public double getElement(int index)(Code) | | Returns the element at the specified index
Parameters:
index - The Index of the element return the element at the specified index |
| getGeometricMean | | public double getGeometricMean()(Code) | | Returns the
geometric mean of the available values
The geometricMean, Double.NaN if no values have been added, or if the productof the available values is less than or equal to 0. |
| getKurtosis | | public double getKurtosis()(Code) | | Returns the Kurtosis of the available values. Kurtosis is a
measure of the "peakedness" of a distribution
The kurtosis, Double.NaN if no values have been added, or 0.0 for a value set <=3. |
| getMax | | public double getMax()(Code) | | Returns the maximum of the available values
The max or Double.NaN if no values have been added. |
| getMean | | public double getMean()(Code) | | Returns the
arithmetic mean of the available values
The mean or Double.NaN if no values have been added. |
| getMin | | public double getMin()(Code) | | Returns the minimum of the available values
The min or Double.NaN if no values have been added. |
| getN | | abstract public long getN()(Code) | | Returns the number of available values
The number of available values |
| getPercentile | | public double getPercentile(double p)(Code) | | Returns an estimate for the pth percentile of the stored values.
The implementation provided here follows the first estimation procedure presented
here.
Preconditions:
0 < p < 100 (otherwise an
IllegalArgumentException is thrown)- at least one value must be stored (returns
Double.NaN
otherwise)
Parameters:
p - the requested percentile (scaled from 0 - 100) An estimate for the pth percentile of the stored data values |
| getSkewness | | public double getSkewness()(Code) | | Returns the skewness of the available values. Skewness is a
measure of the assymetry of a given distribution.
The skewness, Double.NaN if no values have been added or 0.0 for a value set <=2. |
| getSortedValues | | public double[] getSortedValues()(Code) | | Returns the current set of values in an array of double primitives,
sorted in ascending order. The returned array is a fresh
copy of the underlying data -- i.e., it is not a reference to the
stored data.
returns the current set of numbers sorted in ascending order |
| getStandardDeviation | | public double getStandardDeviation()(Code) | | Returns the standard deviation of the available values.
The standard deviation, Double.NaN if no values have been added or 0.0 for a single value set. |
| getSum | | public double getSum()(Code) | | Returns the sum of the values that have been added to Univariate.
The sum or Double.NaN if no values have been added |
| getSumsq | | public double getSumsq()(Code) | | Returns the sum of the squares of the available values.
The sum of the squares or Double.NaN if no values have been added. |
| getValues | | abstract public double[] getValues()(Code) | | Returns the current set of values in an array of double primitives.
The order of addition is preserved. The returned array is a fresh
copy of the underlying data -- i.e., it is not a reference to the
stored data.
returns the current set of numbers in the order in which they were added to this set |
| getVariance | | public double getVariance()(Code) | | Returns the variance of the available values.
The variance, Double.NaN if no values have been added or 0.0 for a single value set. |
| getWindowSize | | abstract public int getWindowSize()(Code) | | Univariate has the ability to return only measures for the
last N elements added to the set of values.
The current window size or -1 if its Infinite. |
| setWindowSize | | abstract public void setWindowSize(int windowSize)(Code) | | WindowSize controls the number of values which contribute
to the values returned by Univariate. For example, if
windowSize is set to 3 and the values {1,2,3,4,5}
have been added in that order
then the available values are {3,4,5} and all
reported statistics will be based on these values
Parameters:
windowSize - sets the size of the window. |
| toString | | public String toString()(Code) | | Generates a text report displaying univariate statistics from values
that have been added. Each statistic is displayed on a separate
line.
String with line feeds displaying statistics |
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