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java.lang.Objectorg.apache.commons.math.random.EmpiricalDistributionImpl
public class EmpiricalDistributionImpl
Implements EmpiricalDistribution
interface. This implementation
uses what amounts to the
Variable Kernel Method with Gaussian smoothing:
Digesting the input file
binCount
"bins."USAGE NOTES:
binCount
is set by default to 1000. A good rule of thumb
is to set the bin count to approximately the length of the input file divided
by 10.
Nested Class Summary | |
---|---|
private class |
EmpiricalDistributionImpl.ArrayDataAdapter
DataAdapter for data provided as array of doubles. |
private class |
EmpiricalDistributionImpl.DataAdapter
Provides methods for computing sampleStats and
beanStats abstracting the source of data. |
private class |
EmpiricalDistributionImpl.DataAdapterFactory
Factory of DataAdapter objects. |
private class |
EmpiricalDistributionImpl.StreamDataAdapter
DataAdapter for data provided through some input stream |
Field Summary | |
---|---|
private int |
binCount
number of bins |
private java.util.List<SummaryStatistics> |
binStats
List of SummaryStatistics objects characterizing the bins |
private double |
delta
Grid size |
private boolean |
loaded
is the distribution loaded? |
private double |
max
Max loaded value |
private double |
min
Min loaded value |
private RandomData |
randomData
RandomData instance to use in repeated calls to getNext() |
private SummaryStatistics |
sampleStats
Sample statistics |
private static long |
serialVersionUID
Serializable version identifier |
private double[] |
upperBounds
upper bounds of subintervals in (0,1) "belonging" to the bins |
Constructor Summary | |
---|---|
EmpiricalDistributionImpl()
Creates a new EmpiricalDistribution with the default bin count. |
|
EmpiricalDistributionImpl(int binCount)
Creates a new EmpiricalDistribution with the specified bin count. |
Method Summary | |
---|---|
private void |
fillBinStats(java.lang.Object in)
Fills binStats array (second pass through data file). |
private int |
findBin(double value)
Returns the index of the bin to which the given value belongs |
int |
getBinCount()
Returns the number of bins. |
java.util.List<SummaryStatistics> |
getBinStats()
Returns a List of SummaryStatistics instances containing
statistics describing the values in each of the bins. |
double[] |
getGeneratorUpperBounds()
Returns a fresh copy of the array of upper bounds of the subintervals of [0,1] used in generating data from the empirical distribution. |
double |
getNextValue()
Generates a random value from this distribution. |
StatisticalSummary |
getSampleStats()
Returns a StatisticalSummary describing this distribution. |
double[] |
getUpperBounds()
Returns a fresh copy of the array of upper bounds for the bins. |
boolean |
isLoaded()
Property indicating whether or not the distribution has been loaded. |
void |
load(double[] in)
Computes the empirical distribution from the provided array of numbers. |
void |
load(java.io.File file)
Computes the empirical distribution from the input file. |
void |
load(java.net.URL url)
Computes the empirical distribution using data read from a URL. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
---|
private static final long serialVersionUID
private final java.util.List<SummaryStatistics> binStats
private SummaryStatistics sampleStats
private double max
private double min
private double delta
private final int binCount
private boolean loaded
private double[] upperBounds
private final RandomData randomData
Constructor Detail |
---|
public EmpiricalDistributionImpl()
public EmpiricalDistributionImpl(int binCount)
binCount
- number of binsMethod Detail |
---|
public void load(double[] in)
load
in interface EmpiricalDistribution
in
- the input data arraypublic void load(java.net.URL url) throws java.io.IOException
load
in interface EmpiricalDistribution
url
- url of the input file
java.io.IOException
- if an IO error occurspublic void load(java.io.File file) throws java.io.IOException
load
in interface EmpiricalDistribution
file
- the input file
java.io.IOException
- if an IO error occursprivate void fillBinStats(java.lang.Object in) throws java.io.IOException
in
- object providing access to the data
java.io.IOException
- if an IO error occursprivate int findBin(double value)
value
- the value whose bin we are trying to find
public double getNextValue() throws java.lang.IllegalStateException
getNextValue
in interface EmpiricalDistribution
java.lang.IllegalStateException
- if the distribution has not been loadedpublic StatisticalSummary getSampleStats()
StatisticalSummary
describing this distribution.
Preconditions:
getSampleStats
in interface EmpiricalDistribution
java.lang.IllegalStateException
- if the distribution has not been loadedpublic int getBinCount()
getBinCount
in interface EmpiricalDistribution
public java.util.List<SummaryStatistics> getBinStats()
SummaryStatistics
instances containing
statistics describing the values in each of the bins. The list is
indexed on the bin number.
getBinStats
in interface EmpiricalDistribution
public double[] getUpperBounds()
Returns a fresh copy of the array of upper bounds for the bins.
Bins are:
[min,upperBounds[0]],(upperBounds[0],upperBounds[1]],...,
(upperBounds[binCount-2], upperBounds[binCount-1] = max].
Note: In versions 1.0-2.0 of commons-math, this method
incorrectly returned the array of probability generator upper
bounds now returned by getGeneratorUpperBounds()
.
getUpperBounds
in interface EmpiricalDistribution
public double[] getGeneratorUpperBounds()
Returns a fresh copy of the array of upper bounds of the subintervals of [0,1] used in generating data from the empirical distribution. Subintervals correspond to bins with lengths proportional to bin counts.
In versions 1.0-2.0 of commons-math, this array was (incorrectly) returned
by getUpperBounds()
.
public boolean isLoaded()
isLoaded
in interface EmpiricalDistribution
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