uk.ac.starlink.ttools.plot2.layer

Class SkyVectorFieldPlotter

java.lang.Object

uk.ac.starlink.ttools.plot2.layer.SkyVectorFieldPlotter

All Implemented Interfaces:

Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

public class SkyVectorFieldPlotter
extends Object
implements Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Plotter that shows a grid of vectors based on averaged vector values on the sky. The gridding is done using HEALPix tiles. It paints a single Decal, no Glyphs.

Note it only works with a SkySurface.

Since:

23 Apr 2026

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SkyVectorFieldPlotter.VectorFieldStyle Style for SkyVectorFieldPlotter.

Field Summary

Fields

Modifier and Type	Field and Description
static ConfigKey<Color>	COLOR_KEY
static ConfigKey<Combiner>	COMBINER_KEY
static ReportKey<StarTable>	FIELDTABLE_REPKEY
static ReportKey<Double>	LATOFFSET_REPKEY
static ConfigKey<Integer>	LEVEL_KEY
static ReportKey<Double>	LONOFFSET_REPKEY
static ConfigKey<Boolean>	RELATIVE_KEY
static ConfigKey<Double>	SCALE_KEY
static ConfigKey<MultiPointShape>	SHAPE_KEY
static ConfigKey<Integer>	THICK_KEY
static ConfigKey<Double>	TRANSPARENCY_KEY

Constructor Summary

Constructors

Constructor and Description
SkyVectorFieldPlotter(boolean hasWeight) Constructor.

Method Summary

Modifier and Type	Method and Description
PlotLayer	createLayer(DataGeom geom, DataSpec dataSpec, SkyVectorFieldPlotter.VectorFieldStyle style) Creates a PlotLayer based on the given geometry, data and style.
SkyVectorFieldPlotter.VectorFieldStyle	createStyle(ConfigMap config) Creates a style that can be used when creating a plot layer.
CoordGroup	getCoordGroup() Returns an object describing which data coordinates are used for this plotter and how they are arranged in supplied DataSpec objects.
String	getPlotterDescription() Returns an XML description of this plotter.
Icon	getPlotterIcon() Returns an icon for this plotter for use in user interface.
String	getPlotterName() Returns the name of this plotter for use in user interface.
Object	getRangeStyleKey(SkyVectorFieldPlotter.VectorFieldStyle style) Returns an opaque object characterising the region of the plot surface covered when using a given plotter style.
ConfigKey<?>[]	getStyleKeys() Returns the configuration keys used to configure style for this plotter.
boolean	hasReports() Indicates whether the drawings produced by this plotter will return general interest report information to upstream plotting code.

Methods inherited from class java.lang.Object

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

Field Detail

LONOFFSET_REPKEY

public static final ReportKey<Double> LONOFFSET_REPKEY

LATOFFSET_REPKEY

public static final ReportKey<Double> LATOFFSET_REPKEY

FIELDTABLE_REPKEY

public static final ReportKey<StarTable> FIELDTABLE_REPKEY

COLOR_KEY

public static final ConfigKey<Color> COLOR_KEY

SHAPE_KEY

public static final ConfigKey<MultiPointShape> SHAPE_KEY

THICK_KEY

public static final ConfigKey<Integer> THICK_KEY

SCALE_KEY

public static final ConfigKey<Double> SCALE_KEY

LEVEL_KEY

public static final ConfigKey<Integer> LEVEL_KEY

COMBINER_KEY

public static final ConfigKey<Combiner> COMBINER_KEY

RELATIVE_KEY

public static final ConfigKey<Boolean> RELATIVE_KEY

TRANSPARENCY_KEY

public static final ConfigKey<Double> TRANSPARENCY_KEY

Constructor Detail

SkyVectorFieldPlotter

public SkyVectorFieldPlotter(boolean hasWeight)

Constructor.

Parameters:

hasWeight - if true, vector values may be weighted

Method Detail

getPlotterName

public String getPlotterName()

Description copied from interface: Plotter

Returns the name of this plotter for use in user interface.

Specified by:

getPlotterName in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Returns:

user-directed plotter name

getPlotterIcon

public Icon getPlotterIcon()

Description copied from interface: Plotter

Returns an icon for this plotter for use in user interface.

Specified by:

getPlotterIcon in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Returns:

plotter icon

getCoordGroup

public CoordGroup getCoordGroup()

Description copied from interface: Plotter

Returns an object describing which data coordinates are used for this plotter and how they are arranged in supplied DataSpec objects.

Specified by:

getCoordGroup in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Returns:

coordinate group

hasReports

public boolean hasReports()

Description copied from interface: Plotter

Indicates whether the drawings produced by this plotter will return general interest report information to upstream plotting code.

Specified by:

hasReports in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Returns:

true if the plot report may return interesting information

See Also:

Drawing.getReport(java.lang.Object)

getPlotterDescription

public String getPlotterDescription()

Description copied from interface: Plotter

Returns an XML description of this plotter.

Note: really this should appear at the LayerType level.

Specified by:

getPlotterDescription in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Returns:

one or more <p> elements

getStyleKeys

public ConfigKey<?>[] getStyleKeys()

Description copied from interface: Plotter

Returns the configuration keys used to configure style for this plotter. The keys in the return value are used in the map supplied to the Plotter.createStyle(uk.ac.starlink.ttools.plot2.config.ConfigMap) method.

Specified by:

getStyleKeys in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Returns:

keys used when creating a style for this plotter.

createStyle

public SkyVectorFieldPlotter.VectorFieldStyle createStyle(ConfigMap config)

Description copied from interface: Plotter

Creates a style that can be used when creating a plot layer. The keys that are significant in the supplied config map are those returned by Plotter.getStyleKeys(). The return value can be used as input to Plotter.createLayer(uk.ac.starlink.ttools.plot2.DataGeom, uk.ac.starlink.ttools.plot2.data.DataSpec, S).

Specified by:

createStyle in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Parameters:

config - map of style configuration items

Returns:

plotter-specific plot style

getRangeStyleKey

public Object getRangeStyleKey(SkyVectorFieldPlotter.VectorFieldStyle style)

Description copied from interface: Plotter

Returns an opaque object characterising the region of the plot surface covered when using a given plotter style. If this object changes between layers produced by this plotter, it provides a hint that it may be necessary to redetermine the axis ranges (using extendCoordinateRanges).

In many cases, such as scatter-plot-like plotters, the range is determined only by the coordinate data (managed by DataSpec inputs) so a null value may be returned. This method is chiefly required by histogram-like plotters for which the region on the plot surface is not the union of the input positions.

Specified by:

getRangeStyleKey in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Parameters:

style - plot style to assess

Returns:

opaque object with equality semantics, or null if axis range is not a function of style

createLayer

public PlotLayer createLayer(DataGeom geom,
                             DataSpec dataSpec,
                             SkyVectorFieldPlotter.VectorFieldStyle style)

Description copied from interface: Plotter

Creates a PlotLayer based on the given geometry, data and style.

The style parameter is the result of a call to Plotter.createStyle(uk.ac.starlink.ttools.plot2.config.ConfigMap).

The dataSpec parameter must contain the coordinates defined by this plotter's CoordGroup.

The pointDataGeom parameter is only used if the CoordGroup.getBasicPositionCount() or CoordGroup.getExtraPositionCount() method from this plotter's CoordGroup return a non-zero value, otherwise the plot does not have point positions.

It is legal to supply null for any of the parameters; if insufficient data is supplied to generate a plot, then the method should return null.

Creating a layer should be cheap; layers may be created and not used.

Specified by:

createLayer in interface Plotter<SkyVectorFieldPlotter.VectorFieldStyle>

Parameters:

geom - indicates base position coordinates and their mapping to points in the data space

dataSpec - specifies the data required for the plot

style - data style as obtained from createStyle

Returns:

new plot layer, or null if no drawing will take place