de.lmu.ifi.dbs.elki.utilities.datastructures.histogram

Class DoubleDynamicHistogram

java.lang.Object

de.lmu.ifi.dbs.elki.utilities.datastructures.histogram.AbstractStaticHistogram

de.lmu.ifi.dbs.elki.utilities.datastructures.histogram.DoubleStaticHistogram

de.lmu.ifi.dbs.elki.utilities.datastructures.histogram.DoubleDynamicHistogram

All Implemented Interfaces:

DoubleHistogram, Histogram

public class DoubleDynamicHistogram
extends DoubleStaticHistogram

A flexible histogram storing double, that can dynamically adapt the number of bins to the data fed into the histogram.

Author:

Erich Schubert

Nested Class Summary

Nested classes/interfaces inherited from class de.lmu.ifi.dbs.elki.utilities.datastructures.histogram.DoubleStaticHistogram

DoubleStaticHistogram.Iter

Field Summary

Fields

Modifier and Type	Field and Description
private double[]	cachec Cache for data to be inserted.
private int	cachefill Cache fill size
private double[]	cachev Cache for data to be inserted.
private int	destsize Destination (minimum) size of the structure.

Fields inherited from class de.lmu.ifi.dbs.elki.utilities.datastructures.histogram.DoubleStaticHistogram

data

Fields inherited from class de.lmu.ifi.dbs.elki.utilities.datastructures.histogram.AbstractStaticHistogram

base, binsize, max, offset, size

Fields inherited from interface de.lmu.ifi.dbs.elki.utilities.datastructures.histogram.Histogram

CACHE_SHIFT

Constructor Summary

Constructors

Constructor and Description
DoubleDynamicHistogram(int bins) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
protected double	downsample(double[] data, int start, int end, int size) Perform downsampling on a number of bins.
double	get(double coord) Get the value at a particular position.
double	getBinsize() Get the size (width) of a bin.
double	getCoverMaximum() Get maximum (covered by bins, not data!)
double	getCoverMinimum() Get minimum (covered by bins, not data!)
int	getNumBins() Get the number of bins actually in use.
void	increment(double coord, double value) Put fresh data into the histogram (or into the cache)
DoubleStaticHistogram.Iter	iter() Get an iterator over all histogram bins.
(package private) void	materialize() Materialize the histogram from the cache.
private void	testResample(double coord) Test (and perform) downsampling when neede.

Methods inherited from class de.lmu.ifi.dbs.elki.utilities.datastructures.histogram.AbstractStaticHistogram

getBinNr, growSize

Methods inherited from class java.lang.Object

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

Field Detail

cachec

private double[] cachec

Cache for data to be inserted.

cachev

private double[] cachev

Cache for data to be inserted.

cachefill

private int cachefill

Cache fill size

destsize

private int destsize

Destination (minimum) size of the structure. At most destsize * 2 bins are allowed.

Constructor Detail

DoubleDynamicHistogram

public DoubleDynamicHistogram(int bins)

Constructor.

Parameters:

bins - Design number of bins - may become twice as large!

Method Detail

materialize

void materialize()

Materialize the histogram from the cache.

get

public double get(double coord)

Description copied from class: DoubleStaticHistogram

Get the value at a particular position.

Overrides:

get in class DoubleStaticHistogram

Parameters:

coord - Coordinate

Returns:

Value

increment

public void increment(double coord,
             double value)

Put fresh data into the histogram (or into the cache)

Specified by:

increment in interface DoubleHistogram

Overrides:

increment in class DoubleStaticHistogram

Parameters:

coord - Coordinate

value - Value

testResample

private void testResample(double coord)

Test (and perform) downsampling when neede.

Parameters:

coord - coordinate to accomodate.

iter

public DoubleStaticHistogram.Iter iter()

Description copied from class: AbstractStaticHistogram

Get an iterator over all histogram bins.

Specified by:

iter in interface DoubleHistogram

Specified by:

iter in interface Histogram

Overrides:

iter in class DoubleStaticHistogram

Returns:

Iterator

getNumBins

public int getNumBins()

Description copied from class: AbstractStaticHistogram

Get the number of bins actually in use.

Specified by:

getNumBins in interface Histogram

Overrides:

getNumBins in class AbstractStaticHistogram

Returns:

number of bins

getBinsize

public double getBinsize()

Description copied from class: AbstractStaticHistogram

Get the size (width) of a bin.

Specified by:

getBinsize in interface Histogram

Overrides:

getBinsize in class AbstractStaticHistogram

Returns:

bin size

getCoverMinimum

public double getCoverMinimum()

Description copied from class: AbstractStaticHistogram

Get minimum (covered by bins, not data!)

Specified by:

getCoverMinimum in interface Histogram

Overrides:

getCoverMinimum in class AbstractStaticHistogram

Returns:

minimum

getCoverMaximum

public double getCoverMaximum()

Description copied from class: AbstractStaticHistogram

Get maximum (covered by bins, not data!)

Specified by:

getCoverMaximum in interface Histogram

Overrides:

getCoverMaximum in class AbstractStaticHistogram

Returns:

maximum

downsample

protected double downsample(double[] data,
                int start,
                int end,
                int size)

Perform downsampling on a number of bins.

Parameters:

data - Data array (needs cast!)

start - Interval start

end - Interval end (exclusive)

size - Intended size - extra bins are assumed to be empty, should be a power of two

Returns:

New bin value