Class DoubleSketch

    • Constructor Detail

      • DoubleSketch

        public DoubleSketch​(int lgK,
                            DoubleSummary.Mode mode)
        Constructs this sketch with given lgK.
        Parameters:
        lgK - Log_base2 of Nominal Entries. See Nominal Entries
        mode - The DoubleSummary mode to be used
      • DoubleSketch

        public DoubleSketch​(int lgK,
                            int lgResizeFactor,
                            float samplingProbability,
                            DoubleSummary.Mode mode)
        Creates this sketch with the following parameters:
        Parameters:
        lgK - Log_base2 of Nominal Entries.
        lgResizeFactor - log2(resizeFactor) - value from 0 to 3:
         0 - no resizing (max size allocated),
         1 - double internal hash table each time it reaches a threshold
         2 - grow four times
         3 - grow eight times (default)
         
        samplingProbability - See Sampling Probability
        mode - The DoubleSummary mode to be used
      • DoubleSketch

        @Deprecated
        public DoubleSketch​(org.apache.datasketches.memory.Memory mem,
                            DoubleSummary.Mode mode)
        Deprecated.
        As of 3.0.0, heapifying an UpdatableSketch is deprecated. This capability will be removed in a future release. Heapifying a CompactSketch is not deprecated.
        Constructs this sketch from a Memory image, which must be from an DoubleSketch, and usually with data.
        Parameters:
        mem - the given Memory
        mode - The DoubleSummary mode to be used
    • Method Detail

      • update

        public void update​(String key,
                           Double value)
        Description copied from class: UpdatableSketch
        Updates this sketch with a String key and U value. The value is passed to update() method of the Summary object associated with the key
        Overrides:
        update in class UpdatableSketch<Double,​DoubleSummary>
        Parameters:
        key - The given String key
        value - The given U value
      • update

        public void update​(long key,
                           Double value)
        Description copied from class: UpdatableSketch
        Updates this sketch with a long key and U value. The value is passed to update() method of the Summary object associated with the key
        Overrides:
        update in class UpdatableSketch<Double,​DoubleSummary>
        Parameters:
        key - The given long key
        value - The given U value
      • getRetainedEntries

        public int getRetainedEntries()
        Specified by:
        getRetainedEntries in class Sketch<S extends Summary>
        Returns:
        number of retained entries
      • getCountLessThanThetaLong

        public int getCountLessThanThetaLong​(long thetaLong)
        Description copied from class: Sketch
        Gets the number of hash values less than the given theta expressed as a long.
        Specified by:
        getCountLessThanThetaLong in class Sketch<S extends Summary>
        Parameters:
        thetaLong - the given theta as a long between zero and Long.MAX_VALUE.
        Returns:
        the number of hash values less than the given thetaLong.
      • getNominalEntries

        public int getNominalEntries()
        Get configured nominal number of entries
        Returns:
        nominal number of entries
      • getLgK

        public int getLgK()
        Get log_base2 of Nominal Entries
        Returns:
        log_base2 of Nominal Entries
      • getSamplingProbability

        public float getSamplingProbability()
        Get configured sampling probability
        Returns:
        sampling probability
      • getCurrentCapacity

        public int getCurrentCapacity()
        Get current capacity
        Returns:
        current capacity
      • getResizeFactor

        public ResizeFactor getResizeFactor()
        Get configured resize factor
        Returns:
        resize factor
      • trim

        public void trim()
        Rebuilds reducing the actual number of entries to the nominal number of entries if needed
      • reset

        public void reset()
        Resets this sketch an empty state.
      • compact

        public CompactSketch<S> compact()
        Converts the current state of the sketch into a compact sketch
        Specified by:
        compact in class Sketch<S extends Summary>
        Returns:
        compact sketch
      • toByteArray

        @Deprecated
        public byte[] toByteArray()
        Deprecated.
        As of 3.0.0, serializing an UpdatableSketch is deprecated. This capability will be removed in a future release. Serializing a CompactSketch is not deprecated.
        This serializes an UpdatableSketch (QuickSelectSketch).
        Specified by:
        toByteArray in class Sketch<S extends Summary>
        Returns:
        serialized representation of an UpdatableSketch (QuickSelectSketch).
      • insertSummary

        protected void insertSummary​(int index,
                                     S summary)