Class StdDevSAggregator<V extends Number>
java.lang.Object
org.apache.derby.impl.sql.execute.VarPAggregator<V>
org.apache.derby.impl.sql.execute.VarSAggregator<V>
org.apache.derby.impl.sql.execute.StdDevSAggregator<V>
- All Implemented Interfaces:
Externalizable
,Serializable
,Aggregator<V,
Double, VarPAggregator<V>>
This class implements the SQL Standard STDDEV_SAMP() aggregator, computing a sample's standard deviation. It relies on VarSAggregator to compute the sample's variance and then applies the textbook definition of standard deviation:
√var_samp()
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.derby.impl.sql.execute.VarPAggregator
VarPAggregator.Sums
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Field Summary
FieldsFields inherited from class org.apache.derby.impl.sql.execute.VarPAggregator
count, sums
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Constructor Summary
Constructors -
Method Summary
Methods inherited from class org.apache.derby.impl.sql.execute.VarSAggregator
computeVar
Methods inherited from class org.apache.derby.impl.sql.execute.VarPAggregator
accumulate, init, merge, readExternal, writeExternal
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Field Details
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serialVersionUID
private static final long serialVersionUID- See Also:
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Constructor Details
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StdDevSAggregator
public StdDevSAggregator()
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Method Details
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terminate
Description copied from interface:Aggregator
Return the result scalar value- Specified by:
terminate
in interfaceAggregator<V extends Number,
Double, VarPAggregator<V extends Number>> - Overrides:
terminate
in classVarPAggregator<V extends Number>
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