StatCounter (Spark 1.0.2 JavaDoc)

Object
- org.apache.spark.util.StatCounter

All Implemented Interfaces:

java.io.Serializable
```
public class StatCounter
extends Object
implements scala.Serializable
```
A class for tracking the statistics of a set of numbers (count, mean and variance) in a numerically robust way. Includes support for merging two StatCounters. Based on Welford and Chan's algorithms for running variance.

See Also:
Serialized Form

Constructor Summary

Constructors
Constructor and Description

StatCounter()
Initialize the StatCounter with no values.

StatCounter(scala.collection.TraversableOnce<Object> values)

Constructors
Constructor and Description
`StatCounter()` Initialize the StatCounter with no values.
`StatCounter(scala.collection.TraversableOnce<Object> values)`

Method Summary

Methods
Modifier and Type	Method and Description
`static StatCounter`	`apply(scala.collection.Seq<Object> values)` Build a StatCounter from a list of values passed as variable-length arguments.
`static StatCounter`	`apply(scala.collection.TraversableOnce<Object> values)` Build a StatCounter from a list of values.
`StatCounter`	`copy()` Clone this StatCounter
`long`	`count()`
`double`	`max()`
`double`	`mean()`
`StatCounter`	`merge(double value)` Add a value into this StatCounter, updating the internal statistics.
`StatCounter`	`merge(StatCounter other)` Merge another StatCounter into this one, adding up the internal statistics.
`StatCounter`	`merge(scala.collection.TraversableOnce<Object> values)` Add multiple values into this StatCounter, updating the internal statistics.
`double`	`min()`
`double`	`sampleStdev()` Return the sample standard deviation of the values, which corrects for bias in estimating the variance by dividing by N-1 instead of N.
`double`	`sampleVariance()` Return the sample variance, which corrects for bias in estimating the variance by dividing by N-1 instead of N.
`double`	`stdev()` Return the standard deviation of the values.
`double`	`sum()`
`String`	`toString()`
`double`	`variance()` Return the variance of the values.

Methods inherited from class Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - StatCounter
```
public StatCounter(scala.collection.TraversableOnce<Object> values)
```
  - StatCounter
```
public StatCounter()
```
    Initialize the StatCounter with no values.
- Method Detail
  - apply
```
public static StatCounter apply(scala.collection.TraversableOnce<Object> values)
```
    Build a StatCounter from a list of values.
  - apply
```
public static StatCounter apply(scala.collection.Seq<Object> values)
```
    Build a StatCounter from a list of values passed as variable-length arguments.
  - merge
```
public StatCounter merge(double value)
```
    Add a value into this StatCounter, updating the internal statistics.
  - merge
```
public StatCounter merge(scala.collection.TraversableOnce<Object> values)
```
    Add multiple values into this StatCounter, updating the internal statistics.
  - merge
```
public StatCounter merge(StatCounter other)
```
    Merge another StatCounter into this one, adding up the internal statistics.
  - copy
```
public StatCounter copy()
```
    Clone this StatCounter
  - count
```
public long count()
```
  - mean
```
public double mean()
```
  - sum
```
public double sum()
```
  - max
```
public double max()
```
  - min
```
public double min()
```
  - variance
```
public double variance()
```
    Return the variance of the values.
  - sampleVariance
```
public double sampleVariance()
```
    Return the sample variance, which corrects for bias in estimating the variance by dividing by N-1 instead of N.
  - stdev
```
public double stdev()
```
    Return the standard deviation of the values.
  - sampleStdev
```
public double sampleStdev()
```
    Return the sample standard deviation of the values, which corrects for bias in estimating the variance by dividing by N-1 instead of N.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class StatCounter

Constructor Summary

Method Summary

Methods inherited from class Object

Constructor Detail

StatCounter

StatCounter

Method Detail

apply

apply

merge

merge

merge

copy

count

mean

sum

max

min

variance

sampleVariance

stdev

sampleStdev

toString