de.lmu.ifi.dbs.elki.math
Class Histogram<T>

java.lang.Object
  de.lmu.ifi.dbs.elki.math.Histogram<T>

Type Parameters:

T - Histogram data type.

All Implemented Interfaces:

Iterable<Pair<Double,T>>

public class Histogram<T>
extends Object
implements Iterable<Pair<Double,T>>

Class to manage a simple Histogram.

Author:

Erich Schubert

Nested Class Summary

static class	Histogram.Constructor<T> Interface to plug in constructors for type T.
protected class	Histogram.Iter Iterator class to iterate over all bins.

Field Summary

protected double	base Array 'base', i.e. the point of 0.0.
protected double	binsize Width of a bin.
protected ArrayList<T>	data Data storage
private Histogram.Constructor<T>	maker Constructor for new elements
protected double	max To avoid introducing an extra bucket for the maximum value.
protected int	offset Array shift to account for negative indices.
protected int	size Size of array storage.

Constructor Summary

Histogram(int bins, double min, double max)
Histogram constructor without 'Constructor' to generate new elements.

Histogram(int bins, double min, double max, Histogram.Constructor<T> maker)
Histogram constructor

Method Summary

static Histogram<Pair<Double,Double>>	DoubleDoubleHistogram(int bins, double min, double max) Convenience constructor for Histograms with pairs of Doubles Uses a constructor to initialize bins with Pair(Double(0),Double(0))
static Histogram<Double>	DoubleHistogram(int bins, double min, double max) Convenience constructor for Double-based Histograms.
T	get(double coord) Get the data at a given Coordinate.
private int	getBinNr(double coord) Compute the bin number.
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!)
ArrayList<T>	getData() Get the raw data.
int	getNumBins() Get the number of bins actually in use.
static Histogram<Integer>	IntHistogram(int bins, double min, double max) Convenience constructor for Integer-based Histograms.
static Histogram<Pair<Integer,Integer>>	IntIntHistogram(int bins, double min, double max) Convenience constructor for Histograms with pairs of Integers Uses a constructor to initialize bins with Pair(Integer(0),Integer(0))
Iterator<Pair<Double,T>>	iterator() Get an iterator over all histogram bins.
private T	make() Call the constructor to produce a new element, if possible.
static Histogram<MeanVariance>	MeanVarianceHistogram(int bins, double min, double max) Convenience constructor for MeanVariance-based Histograms.
void	put(double coord, T d) Put data at a given coordinate.
private void	putBin(int bin, T d) Internal put function to handle the special cases of histogram resizing.

Methods inherited from class java.lang.Object

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

Field Detail

offset

protected int offset

Array shift to account for negative indices.

size

protected int size

Size of array storage.

base

protected double base

Array 'base', i.e. the point of 0.0. Usually the minimum.

max

protected double max

To avoid introducing an extra bucket for the maximum value.

binsize

protected double binsize

Width of a bin.

data

protected ArrayList<T> data

Data storage

maker

private Histogram.Constructor<T> maker

Constructor for new elements

Constructor Detail

Histogram

public Histogram(int bins,
                 double min,
                 double max,
                 Histogram.Constructor<T> maker)

Histogram constructor

Parameters:

bins - Number of bins to use.

min - Minimum Value

max - Maximum Value

maker - Constructor for new elements.

Histogram

public Histogram(int bins,
                 double min,
                 double max)

Histogram constructor without 'Constructor' to generate new elements. Empty bins will be initialized with 'null'.

Parameters:

bins - Number of bins

min - Minimum value

max - Maximum value.

Method Detail

make

private T make()

Call the constructor to produce a new element, if possible.

Returns:

new element or null.

get

public T get(double coord)

Get the data at a given Coordinate.

Parameters:

coord - Coordinate.

Returns:

data element there (which may be a new empty bin or null)

put

public void put(double coord,
                T d)

Put data at a given coordinate. Note: this replaces the contents, it doesn't "add" or "count".

Parameters:

coord -

d -

getBinNr

private int getBinNr(double coord)

Compute the bin number. Has a special case for rounding max down to the last bin.

Parameters:

coord - Coordinate

Returns:

bin number

putBin

private void putBin(int bin,
                    T d)

Internal put function to handle the special cases of histogram resizing.

Parameters:

bin - bin number

d - data to put

getData

public ArrayList<T> getData()

Get the raw data. Note that this does NOT include the coordinates.

Returns:

raw data array.

iterator

public Iterator<Pair<Double,T>> iterator()

Get an iterator over all histogram bins.

Specified by:

iterator in interface Iterable<Pair<Double,T>>

IntHistogram

public static final Histogram<Integer> IntHistogram(int bins,
                                                    double min,
                                                    double max)

Convenience constructor for Integer-based Histograms. Uses a constructor to initialize bins with Integer(0)

Parameters:

bins - Number of bins

min - Minimum coordinate

max - Maximum coordinate

Returns:

New histogram for Integers.

DoubleHistogram

public static final Histogram<Double> DoubleHistogram(int bins,
                                                      double min,
                                                      double max)

Convenience constructor for Double-based Histograms. Uses a constructor to initialize bins with Double(0)

Parameters:

bins - Number of bins

min - Minimum coordinate

max - Maximum coordinate

Returns:

New histogram for Doubles.

IntIntHistogram

public static final Histogram<Pair<Integer,Integer>> IntIntHistogram(int bins,
                                                                     double min,
                                                                     double max)

Convenience constructor for Histograms with pairs of Integers Uses a constructor to initialize bins with Pair(Integer(0),Integer(0))

Parameters:

bins - Number of bins

min - Minimum coordinate

max - Maximum coordinate

Returns:

New histogram for Integer pairs.

DoubleDoubleHistogram

public static final Histogram<Pair<Double,Double>> DoubleDoubleHistogram(int bins,
                                                                         double min,
                                                                         double max)

Convenience constructor for Histograms with pairs of Doubles Uses a constructor to initialize bins with Pair(Double(0),Double(0))

Parameters:

bins - Number of bins

min - Minimum coordinate

max - Maximum coordinate

Returns:

New histogram for Double pairs.

MeanVarianceHistogram

public static final Histogram<MeanVariance> MeanVarianceHistogram(int bins,
                                                                  double min,
                                                                  double max)

Convenience constructor for MeanVariance-based Histograms. Uses a constructor to initialize bins with new MeanVariance objects

Parameters:

bins - Number of bins

min - Minimum coordinate

max - Maximum coordinate

Returns:

New histogram for MeanVariance.

getNumBins

public int getNumBins()

Get the number of bins actually in use.

Returns:

number of bins

getBinsize

public double getBinsize()

Get the size (width) of a bin.

Returns:

bin size

getCoverMinimum

public double getCoverMinimum()

Get minimum (covered by bins, not data!)

Returns:

minimum

getCoverMaximum

public double getCoverMaximum()

Get maximum (covered by bins, not data!)

Returns:

maximum