uk.ac.starlink.ttools.plot2.layer

Class LevelMode

java.lang.Object

uk.ac.starlink.ttools.plot2.layer.LevelMode

@Equality
public abstract class LevelMode
extends Object

Defines a strategy for calculating contour level values from an array of data.

Since:

17 Feb 2013

Author:

Mark Taylor

Field Summary

Fields

Modifier and Type	Field and Description
static LevelMode	EQU Equal-area scaling - levels are spaced to provide equally sized inter-contour regions.
static LevelMode	LINEAR Linear scaling - level values are equally spaced.
static LevelMode	LOG Logarithmic scaling - level logarithms are equally spaced
static LevelMode[]	MODES Known level mode instances.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LevelMode(String name, String description) Constructor.

Method Summary

Modifier and Type	Method and Description
abstract double[]	calculateLevels(NumberArray array, int nLevel, double offset, boolean isCounts) Calculates the contour levels for a given data array.
String	getDescription() Returns a short description of this mode.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

LINEAR

public static LevelMode LINEAR

Linear scaling - level values are equally spaced.

LOG

public static LevelMode LOG

Logarithmic scaling - level logarithms are equally spaced

EQU

public static LevelMode EQU

Equal-area scaling - levels are spaced to provide equally sized inter-contour regions.

MODES

public static final LevelMode[] MODES

Known level mode instances.

Constructor Detail

LevelMode

protected LevelMode(String name,
                    String description)

Constructor.

Parameters:

name - mode name

description - short description of mode

Method Detail

calculateLevels

public abstract double[] calculateLevels(NumberArray array,
                                         int nLevel,
                                         double offset,
                                         boolean isCounts)

Calculates the contour levels for a given data array.

Parameters:

array - data array; NaN elements are permitted and ignored

nLevel - number of requested levels; actual level count may not be the same as this depending on data

offset - offset from zero of the value of the first contour, expected in the range 0..1; adjusting this will sweep contours over all positions

isCounts - true if the values are counts rather than continuously varying; if true, some adjustments are made on the basis of the assumption that differences of scale smaller than 1 don't make much sense

getDescription

public String getDescription()

Returns a short description of this mode.

Returns:

description

toString

public String toString()

Overrides:

toString in class Object