SingleItemSketch (datasketches-java 1.2.0-incubating API)

java.lang.Object
- org.apache.datasketches.theta.Sketch
- - org.apache.datasketches.theta.CompactSketch
  - - org.apache.datasketches.theta.SingleItemSketch

public final class SingleItemSketch
extends CompactSketch

Author:: Lee Rhodes

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static SingleItemSketch`	`create(byte[] data)` Create this sketch with the given byte array.
`static SingleItemSketch`	`create(byte[] data, long seed)` Create this sketch with the given byte array and a seed.
`static SingleItemSketch`	`create(char[] data)` Create this sketch with the given char array.
`static SingleItemSketch`	`create(char[] data, long seed)` Create this sketch with the given char array and a seed.
`static SingleItemSketch`	`create(double datum)` Create this sketch with the given double (or float) datum.
`static SingleItemSketch`	`create(double datum, long seed)` Create this sketch with the given double (or float) datum and a seed.
`static SingleItemSketch`	`create(int[] data)` Create this sketch with the given integer array.
`static SingleItemSketch`	`create(int[] data, long seed)` Create this sketch with the given integer array and a seed.
`static SingleItemSketch`	`create(long datum)` Create this sketch with a long.
`static SingleItemSketch`	`create(long[] data)` Create this sketch with the given long array.
`static SingleItemSketch`	`create(long[] data, long seed)` Create this sketch with the given long array and a seed.
`static SingleItemSketch`	`create(long datum, long seed)` Create this sketch with a long and a seed.
`static SingleItemSketch`	`create(String datum)` Create this sketch with the given String.
`static SingleItemSketch`	`create(String datum, long seed)` Create this sketch with the given String and a seed.
`int`	`getCountLessThanTheta(double theta)` Gets the number of hash values less than the given theta.
`int`	`getCurrentBytes(boolean compact)` Returns the number of storage bytes required for this Sketch in its current state.
`double`	`getEstimate()` Gets the unique count estimate.
`double`	`getLowerBound(int numStdDev)` Gets the approximate lower error bound given the specified number of Standard Deviations.
`int`	`getRetainedEntries(boolean valid)` Returns the number of entries that have been retained by the sketch.
`long`	`getThetaLong()` Gets the value of theta as a long
`double`	`getUpperBound(int numStdDev)` Gets the approximate upper error bound given the specified number of Standard Deviations.
`boolean`	`hasMemory()` Returns true if this sketch's data structure is backed by Memory or WritableMemory.
`static SingleItemSketch`	`heapify(org.apache.datasketches.memory.Memory srcMem)` Creates a SingleItemSketch on the heap given a SingleItemSketch Memory image and assumes the DEFAULT_UPDATE_SEED.
`static SingleItemSketch`	`heapify(org.apache.datasketches.memory.Memory srcMem, long seed)` Creates a SingleItemSketch on the heap given a SingleItemSketch Memory image and a seed.
`boolean`	`isDirect()` Returns true if the this sketch's internal data structure is backed by direct (off-heap) Memory.
`boolean`	`isEmpty()` See Empty
`boolean`	`isOrdered()` Returns true if internal cache is ordered
`HashIterator`	`iterator()` Returns a HashIterator that can be used to iterate over the retained hash values of the Theta sketch.
`byte[]`	`toByteArray()` Serialize this sketch to a byte array form.

Methods inherited from class org.apache.datasketches.theta.CompactSketch
compact, compact, getFamily, isCompact

Methods inherited from class org.apache.datasketches.theta.Sketch
getMaxCompactSketchBytes, getMaxUpdateSketchBytes, getRetainedEntries, getSerializationVersion, getTheta, isEstimationMode, isSameResource, toString, toString, toString, toString, wrap, wrap

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Method Detail
  - heapify
```
public static SingleItemSketch heapify(org.apache.datasketches.memory.Memory srcMem)
```
    Creates a SingleItemSketch on the heap given a SingleItemSketch Memory image and assumes the DEFAULT_UPDATE_SEED.
    
    Parameters:
    
    srcMem - the Memory to be heapified. It must be a least 16 bytes.
    
    Returns:
    
    a SingleItemSketch
  - heapify
```
public static SingleItemSketch heapify(org.apache.datasketches.memory.Memory srcMem,
                                       long seed)
```
    Creates a SingleItemSketch on the heap given a SingleItemSketch Memory image and a seed. Checks the seed hash of the given Memory against a hash of the given seed.
    
    Parameters:
    
    srcMem - the Memory to be heapified
    
    seed - a given hash seed
    
    Returns:
    
    a SingleItemSketch
  - create
```
public static SingleItemSketch create(long datum)
```
    Create this sketch with a long.
    
    Parameters:
    
    datum - The given long datum.
    
    Returns:
    
    a SingleItemSketch
  - create
```
public static SingleItemSketch create(double datum)
```
    Create this sketch with the given double (or float) datum. The double will be converted to a long using Double.doubleToLongBits(datum), which normalizes all NaN values to a single NaN representation. Plus and minus zero will be normalized to plus zero. The special floating-point values NaN and +/- Infinity are treated as distinct.
    
    Parameters:
    
    datum - The given double datum.
    
    Returns:
    
    a SingleItemSketch
  - create
```
public static SingleItemSketch create(String datum)
```
    Create this sketch with the given String. The string is converted to a byte array using UTF8 encoding. If the string is null or empty no create attempt is made and the method returns null.
    Note: this will not produce the same hash values as the create(char[]) method and will generally be a little slower depending on the complexity of the UTF8 encoding.
    
    Parameters:
    
    datum - The given String.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(byte[] data)
```
    Create this sketch with the given byte array. If the byte array is null or empty no create attempt is made and the method returns null.
    
    Parameters:
    
    data - The given byte array.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(char[] data)
```
    Create this sketch with the given char array. If the char array is null or empty no create attempt is made and the method returns null.
    Note: this will not produce the same output hash values as the create(String) method but will be a little faster as it avoids the complexity of the UTF8 encoding.
    
    Parameters:
    
    data - The given char array.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(int[] data)
```
    Create this sketch with the given integer array. If the integer array is null or empty no create attempt is made and the method returns null.
    
    Parameters:
    
    data - The given int array.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(long[] data)
```
    Create this sketch with the given long array. If the long array is null or empty no create attempt is made and the method returns null.
    
    Parameters:
    
    data - The given long array.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(long datum,
                                      long seed)
```
    Create this sketch with a long and a seed.
    
    Parameters:
    
    datum - The given long datum.
    
    seed - used to hash the given value.
    
    Returns:
    
    a SingleItemSketch
  - create
```
public static SingleItemSketch create(double datum,
                                      long seed)
```
    Create this sketch with the given double (or float) datum and a seed. The double will be converted to a long using Double.doubleToLongBits(datum), which normalizes all NaN values to a single NaN representation. Plus and minus zero will be normalized to plus zero. The special floating-point values NaN and +/- Infinity are treated as distinct.
    
    Parameters:
    
    datum - The given double datum.
    
    seed - used to hash the given value.
    
    Returns:
    
    a SingleItemSketch
  - create
```
public static SingleItemSketch create(String datum,
                                      long seed)
```
    Create this sketch with the given String and a seed. The string is converted to a byte array using UTF8 encoding. If the string is null or empty no create attempt is made and the method returns null.
    Note: this will not produce the same output hash values as the create(char[]) method and will generally be a little slower depending on the complexity of the UTF8 encoding.
    
    Parameters:
    
    datum - The given String.
    
    seed - used to hash the given value.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(byte[] data,
                                      long seed)
```
    Create this sketch with the given byte array and a seed. If the byte array is null or empty no create attempt is made and the method returns null.
    
    Parameters:
    
    data - The given byte array.
    
    seed - used to hash the given value.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(char[] data,
                                      long seed)
```
    Create this sketch with the given char array and a seed. If the char array is null or empty no create attempt is made and the method returns null.
    Note: this will not produce the same output hash values as the create(String) method but will be a little faster as it avoids the complexity of the UTF8 encoding.
    
    Parameters:
    
    data - The given char array.
    
    seed - used to hash the given value.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(int[] data,
                                      long seed)
```
    Create this sketch with the given integer array and a seed. If the integer array is null or empty no create attempt is made and the method returns null.
    
    Parameters:
    
    data - The given int array.
    
    seed - used to hash the given value.
    
    Returns:
    
    a SingleItemSketch or null
  - create
```
public static SingleItemSketch create(long[] data,
                                      long seed)
```
    Create this sketch with the given long array and a seed. If the long array is null or empty no create attempt is made and the method returns null.
    
    Parameters:
    
    data - The given long array.
    
    seed - used to hash the given value.
    
    Returns:
    
    a SingleItemSketch or null
  - getCountLessThanTheta
```
public int getCountLessThanTheta(double theta)
```
    Description copied from class: Sketch
    
    Gets the number of hash values less than the given theta.
    
    Overrides:
    
    getCountLessThanTheta in class Sketch
    
    Parameters:
    
    theta - the given theta as a double between zero and one.
    
    Returns:
    
    the number of hash values less than the given theta.
  - getCurrentBytes
```
public int getCurrentBytes(boolean compact)
```
    Description copied from class: Sketch
    
    Returns the number of storage bytes required for this Sketch in its current state.
    
    Specified by:
    
    getCurrentBytes in class Sketch
    
    Parameters:
    
    compact - if true, returns the bytes required for compact form. If this sketch is already in compact form this parameter is ignored.
    
    Returns:
    
    the number of storage bytes required for this sketch
  - getEstimate
```
public double getEstimate()
```
    Description copied from class: Sketch
    
    Gets the unique count estimate.
    
    Overrides:
    
    getEstimate in class Sketch
    
    Returns:
    
    the sketch's best estimate of the cardinality of the input stream.
  - iterator
```
public HashIterator iterator()
```
    Description copied from class: Sketch
    
    Returns a HashIterator that can be used to iterate over the retained hash values of the Theta sketch.
    
    Specified by:
    
    iterator in class Sketch
    
    Returns:
    
    a HashIterator that can be used to iterate over the retained hash values of the Theta sketch.
  - getLowerBound
```
public double getLowerBound(int numStdDev)
```
    Description copied from class: Sketch
    
    Gets the approximate lower error bound given the specified number of Standard Deviations. This will return getEstimate() if isEmpty() is true.
    
    Overrides:
    
    getLowerBound in class Sketch
    
    Parameters:
    
    numStdDev - See Number of Standard Deviations
    
    Returns:
    
    the lower bound.
  - getRetainedEntries
```
public int getRetainedEntries(boolean valid)
```
    Description copied from class: Sketch
    
    Returns the number of entries that have been retained by the sketch.
    
    Specified by:
    
    getRetainedEntries in class Sketch
    
    Parameters:
    
    valid - if true, returns the number of valid entries, which are less than theta and used for estimation. Otherwise, return the number of all entries, valid or not, that are currently in the internal sketch cache.
    
    Returns:
    
    the number of retained entries
  - getThetaLong
```
public long getThetaLong()
```
    Description copied from class: Sketch
    
    Gets the value of theta as a long
    
    Specified by:
    
    getThetaLong in class Sketch
    
    Returns:
    
    the value of theta as a long
  - getUpperBound
```
public double getUpperBound(int numStdDev)
```
    Description copied from class: Sketch
    
    Gets the approximate upper error bound given the specified number of Standard Deviations. This will return getEstimate() if isEmpty() is true.
    
    Overrides:
    
    getUpperBound in class Sketch
    
    Parameters:
    
    numStdDev - See Number of Standard Deviations
    
    Returns:
    
    the upper bound.
  - hasMemory
```
public boolean hasMemory()
```
    Description copied from class: Sketch
    
    Returns true if this sketch's data structure is backed by Memory or WritableMemory.
    
    Specified by:
    
    hasMemory in class Sketch
    
    Returns:
    
    true if this sketch's data structure is backed by Memory or WritableMemory.
  - isDirect
```
public boolean isDirect()
```
    Description copied from class: Sketch
    
    Returns true if the this sketch's internal data structure is backed by direct (off-heap) Memory.
    
    Specified by:
    
    isDirect in class Sketch
    
    Returns:
    
    true if the this sketch's internal data structure is backed by direct (off-heap) Memory.
  - isEmpty
```
public boolean isEmpty()
```
    Description copied from class: Sketch
    
    See Empty
    
    Specified by:
    
    isEmpty in class Sketch
    
    Returns:
    
    true if empty.
  - isOrdered
```
public boolean isOrdered()
```
    Description copied from class: Sketch
    
    Returns true if internal cache is ordered
    
    Specified by:
    
    isOrdered in class Sketch
    
    Returns:
    
    true if internal cache is ordered
  - toByteArray
```
public byte[] toByteArray()
```
    Description copied from class: Sketch
    
    Serialize this sketch to a byte array form.
    
    Specified by:
    
    toByteArray in class Sketch
    
    Returns:
    
    byte array of this sketch

Class SingleItemSketch

Method Summary

Methods inherited from class org.apache.datasketches.theta.CompactSketch

Methods inherited from class org.apache.datasketches.theta.Sketch

Methods inherited from class java.lang.Object

Method Detail

heapify

heapify

create

create

create

create

create

create

create

create

create

create

create

create

create

create

getCountLessThanTheta

getCurrentBytes

getEstimate

iterator

getLowerBound

getRetainedEntries

getThetaLong

getUpperBound

hasMemory

isDirect

isEmpty

isOrdered

toByteArray