Serializable
, DoubleConsumer
, AggregatableStatistic<StreamingStatistics>
, StatisticalSummary
public class StreamingStatistics extends Object implements StatisticalSummary, AggregatableStatistic<StreamingStatistics>, DoubleConsumer, Serializable
addValue
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 pass true
to the constructor or use a
StreamingStatistics.StreamingStatisticsBuilder
to configure an instance with percentiles turned
on. Other stats can also be selectively disabled using
StreamingStatisticsBulder
.
Note: This class is not thread-safe.
Modifier and Type | Class | Description |
---|---|---|
static class |
StreamingStatistics.StreamingStatisticsBuilder |
Builder for StreamingStatistics instances.
|
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.
|
Modifier and Type | Method | Description |
---|---|---|
void |
accept(double value) |
|
void |
addValue(double value) |
Add a value to the data
|
void |
aggregate(StreamingStatistics other) |
Aggregates the provided instance into this instance.
|
static StreamingStatistics.StreamingStatisticsBuilder |
builder() |
Returns a
StreamingStatistics.StreamingStatisticsBuilder to source configured
StreamingStatistics 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 iff
object is a StreamingStatistics
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 values
|
double |
getMean() |
Returns the
arithmetic mean of the available values
|
double |
getMedian() |
Returns an estimate of the median of the values that have been entered.
|
double |
getMin() |
Returns the minimum of the available values
|
long |
getN() |
Returns the number of available values
|
double |
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 a
StatisticalSummaryValues 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.
|
aggregate, aggregate
andThen
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
aggregate, aggregate
public StreamingStatistics()
public StreamingStatistics(boolean computePercentiles)
computePercentiles
- whether or not percentiles are maintainedpublic StreamingStatistics copy()
public StatisticalSummary getSummary()
StatisticalSummaryValues
instance reporting current
statistics.public void addValue(double value)
value
- the value to addpublic void accept(double value)
accept
in interface DoubleConsumer
public void clear()
public long getN()
getN
in interface StatisticalSummary
public double getMax()
getMax
in interface StatisticalSummary
public double getMin()
getMin
in interface StatisticalSummary
public double getSum()
getSum
in interface StatisticalSummary
public double getSumOfSquares()
Double.NaN is returned if no values have been added.
public double getMean()
getMean
in interface StatisticalSummary
public double getVariance()
getVariance
in interface StatisticalSummary
public double getPopulationVariance()
Double.NaN is returned if no values have been added.
public double getGeometricMean()
Double.NaN is returned if no values have been added.
public double getSumOfLogs()
Double.NaN is returned if no values have been added.
public double getSecondMoment()
Returns Double.NaN
if no data values have been added and
returns 0
if there is just one value in the data set.
public double getQuadraticMean()
Double.NaN
if no values
have been added.public double getStandardDeviation()
Double.NaN is returned if no values have been added.
getStandardDeviation
in interface StatisticalSummary
public double getMedian()
RandomPercentile
for a description of the algorithm used for large
data streams.public double getPercentile(double percentile)
RandomPercentile
for a description of the algorithm used for large
data streams.percentile
- the desired percentile (must be between 0 and 100)public void aggregate(StreamingStatistics other)
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.
aggregate
in interface AggregatableStatistic<StreamingStatistics>
other
- the instance to aggregate into this instancepublic String toString()
public boolean equals(Object object)
object
is a StreamingStatistics
instance and all statistics have the same values as this.public int hashCode()
public static StreamingStatistics.StreamingStatisticsBuilder builder()
StreamingStatistics.StreamingStatisticsBuilder
to source configured
StreamingStatistics
instances.Copyright © 2016–2018 Hipparchus.org. All rights reserved.