java.io.Externalizable
, java.io.Serializable
, Aggregator<V,java.lang.Double,VarPAggregator<V>>
public class StdDevPAggregator<V extends java.lang.Number> extends VarPAggregator<V>
This class implements the SQL Standard STDDEV_POP() aggregator, computing a population's standard deviation. It relies on VarPAggregator to compute the population variance and then applies the textbook definition of standard deviation:
√var_pop()
VarPAggregator.Sums
Modifier and Type | Field | Description |
---|---|---|
private static long |
serialVersionUID |
count, sums
Constructor | Description |
---|---|
StdDevPAggregator() |
Modifier and Type | Method | Description |
---|---|---|
java.lang.Double |
terminate() |
Return the result scalar value
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
accumulate, computeVar, init, merge, readExternal, writeExternal
private static final long serialVersionUID
public java.lang.Double terminate()
Aggregator
terminate
in interface Aggregator<V extends java.lang.Number,java.lang.Double,VarPAggregator<V extends java.lang.Number>>
terminate
in class VarPAggregator<V extends java.lang.Number>
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