org.apache.mahout.cf.taste.impl.common
Class FullRunningAverageAndStdDev
java.lang.Object
org.apache.mahout.cf.taste.impl.common.FullRunningAverage
org.apache.mahout.cf.taste.impl.common.FullRunningAverageAndStdDev
- All Implemented Interfaces:
- Serializable, RunningAverage, RunningAverageAndStdDev
public final class FullRunningAverageAndStdDev
- extends FullRunningAverage
- implements RunningAverageAndStdDev
Extends FullRunningAverage to add a running standard deviation computation.
Uses Welford's method, as described at http://www.johndcook.com/standard_deviation.html
- See Also:
- Serialized Form
FullRunningAverageAndStdDev
public FullRunningAverageAndStdDev()
FullRunningAverageAndStdDev
public FullRunningAverageAndStdDev(int count,
double average,
double mk,
double sk)
getMk
public double getMk()
getSk
public double getSk()
getStandardDeviation
public double getStandardDeviation()
- Specified by:
getStandardDeviation in interface RunningAverageAndStdDev
- Returns:
- standard deviation of data
addDatum
public void addDatum(double datum)
- Specified by:
addDatum in interface RunningAverage- Overrides:
addDatum in class FullRunningAverage
- Parameters:
datum - new item to add to the running average
removeDatum
public void removeDatum(double datum)
- Specified by:
removeDatum in interface RunningAverage- Overrides:
removeDatum in class FullRunningAverage
- Parameters:
datum - item to remove to the running average
changeDatum
public void changeDatum(double delta)
- Specified by:
changeDatum in interface RunningAverage- Overrides:
changeDatum in class FullRunningAverage
- Parameters:
delta - amount by which to change a datum in the running average
- Throws:
UnsupportedOperationException
inverse
public RunningAverageAndStdDev inverse()
- Specified by:
inverse in interface RunningAverage- Specified by:
inverse in interface RunningAverageAndStdDev- Overrides:
inverse in class FullRunningAverage
- Returns:
- a (possibly immutable) object whose average is the negative of this object's
toString
public String toString()
- Overrides:
toString in class FullRunningAverage
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