Package org.apache.datasketches.fdt

Class PostProcessor

java.lang.Object

org.apache.datasketches.fdt.PostProcessor

public class PostProcessor
extends Object

This processes the contents of a FDT sketch to extract the primary keys with the most frequent unique combinations of the non-primary dimensions. The source sketch is not modified.

Author:

Lee Rhodes

Constructor Summary

Constructors

Constructor	Description
PostProcessor(FdtSketch sketch, Group group, char sep)	Construct with a populated FdtSketch

Method Summary

Modifier and Type	Method	Description
int	getGroupCount()	Returns the number of groups in the final sketch.
List<Group>	getGroupList(int[] priKeyIndices, int numStdDev, int limit)	Return the most frequent Groups associated with Primary Keys based on the size of the groups.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PostProcessor

public PostProcessor(FdtSketch sketch,
                     Group group,
                     char sep)

Construct with a populated FdtSketch

Parameters:

sketch - the given sketch to query.

group - the Group

sep - the separator character

Method Detail

getGroupCount

public int getGroupCount()

Returns the number of groups in the final sketch.

Returns:

the number of groups in the final sketch.

getGroupList

public List<Group> getGroupList(int[] priKeyIndices,
                                int numStdDev,
                                int limit)

Return the most frequent Groups associated with Primary Keys based on the size of the groups.

Parameters:

priKeyIndices - the indices of the primary dimensions

numStdDev - the number of standard deviations for the error bounds, this value is an integer and must be one of 1, 2, or 3. See Number of Standard Deviations

limit - the maximum number of rows to return. If ≤ 0, all rows will be returned.

Returns:

the most frequent Groups associated with Primary Keys based on the size of the groups.