Package org.apache.datasketches.theta

The theta package contains all the sketch classes that are members of the Theta Sketch Framework.

See: Description

Interface Summary

Interface	Description
HashIterator	This is used to iterate over the retained hash values of the Theta sketch.

Class Summary

Class	Description
AnotB	The API for the set difference operation A and not B operations.
CompactSketch	The parent class of all the CompactSketches.
Intersection	The API for intersection operations
JaccardSimilarity	Jaccard similarity of two Theta Sketches.
PairwiseSetOperations	Set Operations where the arguments are presented in pairs as in C = Op(A,B).
SetOperation	The parent API for all Set Operations
SetOperationBuilder	For building a new SetOperation.
SingleItemSketch
Sketch	The top-level class for all sketches.
Sketches	This class brings together the common sketch and set operation creation methods and the public static methods into one place.
Union	The API for Union operations
UpdateSketch	The parent class for the Update Sketch families, such as QuickSelect and Alpha.
UpdateSketchBuilder	For building a new UpdateSketch.

Enum Summary

Enum	Description
UpdateReturnState	See Update Return State

Package org.apache.datasketches.theta Description

The theta package contains all the sketch classes that are members of the Theta Sketch Framework. The basic sketching functionality in this package is also accessible from Hadoop Pig UDFs found in the sketches-pig repository, and from Hadoop Hive UADFs and UDFs found in the sketches-hive repository.

Simple Java Example

Note: The complete example code can be found in the parallel package under src/test/java and with the class name "ExamplesTest.java".

  public void SimpleCountingSketch() {
    int k = 4096;
    int u = 1000000;
    
    UpdateSketch sketch = UpdateSketch.builder().build(k);
    for (int i = 0; i < u; i++) {
      sketch.update(i);
    }
    
    println(sketch.toString());
  }

### HeapQuickSelectSketch SUMMARY: 
   Nominal Entries (k)     : 4096
   Estimate                : 1002714.745231455
   Upper Bound, 95% conf   : 1027777.3354974985
   Lower Bound, 95% conf   : 978261.4472857157
   p                       : 1.0
   Theta (double)          : 0.00654223948655085
   Theta (long)            : 60341508738660257
   Theta (long, hex        : 00d66048519437a1
   EstMode?                : true
   Empty?                  : false
   Resize Factor           : 8
   Array Size Entries      : 8192
   Retained Entries        : 6560
   Update Seed             : 9001
   Seed Hash               : ffff93cc
### END SKETCH SUMMARY

Author:

Lee Rhodes