Class StreamingStatistics
 java.lang.Object

 org.hipparchus.stat.descriptive.StreamingStatistics

 All Implemented Interfaces:
Serializable
,DoubleConsumer
,AggregatableStatistic<StreamingStatistics>
,StatisticalSummary
public class StreamingStatistics extends Object implements StatisticalSummary, AggregatableStatistic<StreamingStatistics>, DoubleConsumer, Serializable
Computes summary statistics for a stream of data values added using theaddValue
method. The data values are not stored in memory, so this class can be used to compute statistics for very large data streams.By default, all statistics other than percentiles are maintained. Percentile calculations use an embedded
RandomPercentile
which carries more memory and compute overhead than the other statistics, so it is disabled by default. To enable percentiles, either passtrue
to the constructor or use aStreamingStatistics.StreamingStatisticsBuilder
to configure an instance with percentiles turned on. Other stats can also be selectively disabled usingStreamingStatisticsBulder
.Note: This class is not threadsafe.
 See Also:
 Serialized Form


Nested Class Summary
Nested Classes Modifier and Type Class Description static class
StreamingStatistics.StreamingStatisticsBuilder
Builder for StreamingStatistics instances.

Constructor Summary
Constructors Constructor Description StreamingStatistics()
Construct a new StreamingStatistics instance, maintaining all statistics other than percentiles.StreamingStatistics(boolean computePercentiles)
Construct a new StreamingStatistics instance, maintaining all statistics other than percentiles and with/without percentiles per the argument.

Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description void
accept(double value)
void
addValue(double value)
Add a value to the datavoid
aggregate(StreamingStatistics other)
Aggregates the provided instance into this instance.static StreamingStatistics.StreamingStatisticsBuilder
builder()
Returns aStreamingStatistics.StreamingStatisticsBuilder
to source configuredStreamingStatistics
instances.void
clear()
Resets all statistics and storage.StreamingStatistics
copy()
Returns a copy of this StreamingStatistics instance with the same internal state.boolean
equals(Object object)
Returns true iffobject
is aStreamingStatistics
instance and all statistics have the same values as this.double
getGeometricMean()
Returns the geometric mean of the values that have been added.double
getMax()
Returns the maximum of the available valuesdouble
getMean()
Returns the arithmetic mean of the available valuesdouble
getMedian()
Returns an estimate of the median of the values that have been entered.double
getMin()
Returns the minimum of the available valueslong
getN()
Returns the number of available valuesdouble
getPercentile(double percentile)
Returns an estimate of the given percentile of the values that have been entered.double
getPopulationVariance()
Returns the population variance of the values that have been added.double
getQuadraticMean()
Returns the quadratic mean, a.k.a.double
getSecondMoment()
Returns a statistic related to the Second Central Moment.double
getStandardDeviation()
Returns the standard deviation of the values that have been added.double
getSum()
Returns the sum of the values that have been added to Univariate.StatisticalSummary
getSummary()
Return aStatisticalSummaryValues
instance reporting current statistics.double
getSumOfLogs()
Returns the sum of the logs of the values that have been added.double
getSumOfSquares()
Returns the sum of the squares of the values that have been added.double
getVariance()
Returns the variance of the available values.int
hashCode()
Returns hash code based on values of statistics.String
toString()
Generates a text report displaying summary statistics from values that have been added.
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.hipparchus.stat.descriptive.AggregatableStatistic
aggregate, aggregate

Methods inherited from interface java.util.function.DoubleConsumer
andThen




Constructor Detail

StreamingStatistics
public StreamingStatistics()
Construct a new StreamingStatistics instance, maintaining all statistics other than percentiles.

StreamingStatistics
public StreamingStatistics(boolean computePercentiles)
Construct a new StreamingStatistics instance, maintaining all statistics other than percentiles and with/without percentiles per the argument. Parameters:
computePercentiles
 whether or not percentiles are maintained


Method Detail

copy
public StreamingStatistics copy()
Returns a copy of this StreamingStatistics instance with the same internal state. Returns:
 a copy of this

getSummary
public StatisticalSummary getSummary()
Return aStatisticalSummaryValues
instance reporting current statistics. Returns:
 Current values of statistics

addValue
public void addValue(double value)
Add a value to the data Parameters:
value
 the value to add

accept
public void accept(double value)
 Specified by:
accept
in interfaceDoubleConsumer

clear
public void clear()
Resets all statistics and storage.

getN
public long getN()
Returns the number of available values Specified by:
getN
in interfaceStatisticalSummary
 Returns:
 The number of available values

getMax
public double getMax()
Returns the maximum of the available values Specified by:
getMax
in interfaceStatisticalSummary
 Returns:
 The max or Double.NaN if no values have been added.

getMin
public double getMin()
Returns the minimum of the available values Specified by:
getMin
in interfaceStatisticalSummary
 Returns:
 The min or Double.NaN if no values have been added.

getSum
public double getSum()
Returns the sum of the values that have been added to Univariate. Specified by:
getSum
in interfaceStatisticalSummary
 Returns:
 The sum or Double.NaN if no values have been added

getSumOfSquares
public double getSumOfSquares()
Returns the sum of the squares of the values that have been added.Double.NaN is returned if no values have been added.
 Returns:
 The sum of squares

getMean
public double getMean()
Returns the arithmetic mean of the available values Specified by:
getMean
in interfaceStatisticalSummary
 Returns:
 The mean or Double.NaN if no values have been added.

getVariance
public double getVariance()
Returns the variance of the available values. Specified by:
getVariance
in interfaceStatisticalSummary
 Returns:
 The variance, Double.NaN if no values have been added or 0.0 for a single value set.

getPopulationVariance
public double getPopulationVariance()
Returns the population variance of the values that have been added.Double.NaN is returned if no values have been added.
 Returns:
 the population variance

getGeometricMean
public double getGeometricMean()
Returns the geometric mean of the values that have been added.Double.NaN is returned if no values have been added.
 Returns:
 the geometric mean

getSumOfLogs
public double getSumOfLogs()
Returns the sum of the logs of the values that have been added.Double.NaN is returned if no values have been added.
 Returns:
 the sum of logs

getSecondMoment
public double getSecondMoment()
Returns a statistic related to the Second Central Moment. Specifically, what is returned is the sum of squared deviations from the sample mean among the values that have been added.Returns
Double.NaN
if no data values have been added and returns0
if there is just one value in the data set. Returns:
 second central moment statistic

getQuadraticMean
public double getQuadraticMean()
Returns the quadratic mean, a.k.a. rootmeansquare of the available values Returns:
 The quadratic mean or
Double.NaN
if no values have been added.

getStandardDeviation
public double getStandardDeviation()
Returns the standard deviation of the values that have been added.Double.NaN is returned if no values have been added.
 Specified by:
getStandardDeviation
in interfaceStatisticalSummary
 Returns:
 the standard deviation

getMedian
public double getMedian()
Returns an estimate of the median of the values that have been entered. SeeRandomPercentile
for a description of the algorithm used for large data streams. Returns:
 the median

getPercentile
public double getPercentile(double percentile)
Returns an estimate of the given percentile of the values that have been entered. SeeRandomPercentile
for a description of the algorithm used for large data streams. Parameters:
percentile
 the desired percentile (must be between 0 and 100) Returns:
 estimated percentile

aggregate
public void aggregate(StreamingStatistics other)
Aggregates the provided instance into this instance.This method can be used to combine statistics computed over partitions or subsamples  i.e., the value of this instance after this operation should be the same as if a single statistic would have been applied over the combined dataset. Statistics are aggregated only when both this and other are maintaining them. For example, if this.computeMoments is false, but other.computeMoments is true, the moment data in other will be lost.
 Specified by:
aggregate
in interfaceAggregatableStatistic<StreamingStatistics>
 Parameters:
other
 the instance to aggregate into this instance

toString
public String toString()
Generates a text report displaying summary statistics from values that have been added.

equals
public boolean equals(Object object)
Returns true iffobject
is aStreamingStatistics
instance and all statistics have the same values as this.

hashCode
public int hashCode()
Returns hash code based on values of statistics.

builder
public static StreamingStatistics.StreamingStatisticsBuilder builder()
Returns aStreamingStatistics.StreamingStatisticsBuilder
to source configuredStreamingStatistics
instances. Returns:
 a StreamingStatisticsBuilder instance

