uk.ac.starlink.ttools.plot2.layer

Class BinMapper

java.lang.Object

uk.ac.starlink.ttools.plot2.layer.BinMapper

@Equality
public class BinMapper
extends Object

Maps axis values to bin indices.

Since:

16 Jan 2017

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
BinMapper(Scale scale, double scaleWidth, double binPhase, double dpoint) Constructor.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
int	getBinIndex(double dvalue) Returns the bin index for a given value.
double[]	getBinLimits(int index) Returns the bin limits for a given bin index.
int	hashCode()

Methods inherited from class java.lang.Object

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

Constructor Detail

BinMapper

public BinMapper(Scale scale,
                 double scaleWidth,
                 double binPhase,
                 double dpoint)

Constructor.

The dpoint parameter is used internally to determine the zero point of the bins. In principle this should make no difference to behaviour, but in case that the data is situated a very long way from 1, setting it close to the actual data point locations may avoid rounding errors.

Parameters:

scale - axis scaling

scaleWidth - extent of bins in scale units

binPhase - determines sub-bin boundary shifts along axis, normally in range 0..1

dpoint - representative data space point on axis which bins are situated

Method Detail

getBinIndex

public int getBinIndex(double dvalue)

Returns the bin index for a given value. In case of an invalid value (NaN, or non-positive for log scale), behaviour is undefined (quite likely zero will be returned).

Parameters:

dvalue - valid axis value in data space

Returns:

bin index

getBinLimits

public double[] getBinLimits(int index)

Returns the bin limits for a given bin index.

Parameters:

index - bin index

Returns:

(lower,upper) bin limits

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object