uk.ac.starlink.ttools.plot2.layer

Class SkyDensityPlotter

java.lang.Object

uk.ac.starlink.ttools.plot2.layer.SkyDensityPlotter

All Implemented Interfaces:

Plotter<SkyDensityPlotter.SkyDenseStyle>

public class SkyDensityPlotter
extends Object
implements Plotter<SkyDensityPlotter.SkyDenseStyle>

Plotter that plots a genuine density map on a SkySurface. It paints a single Decal, no Glyphs.

Note it only works with a SkySurface.

Since:

20 Sep 2015

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SkyDensityPlotter.SkyDenseStyle Style for configuring with the sky density plot.

Field Summary

Fields

Modifier and Type	Field and Description
static PerUnitConfigKey<SolidAngleUnit>	ANGLE_KEY Config key for solid angle units.
static ConfigKey<Combiner>	COMBINER_KEY Config key for combination mode.
static ReportKey<Double>	TILESIZE_REPKEY Report key for HEALPix tile area in square degrees.
static ConfigKey<Double>	TRANSPARENCY_KEY Config key for transparency.

Constructor Summary

Constructors

Constructor and Description
SkyDensityPlotter(boolean transparent, boolean hasWeight) Constructor.

Method Summary

Modifier and Type	Method and Description
PlotLayer	createLayer(DataGeom geom, DataSpec dataSpec, SkyDensityPlotter.SkyDenseStyle style) Creates a PlotLayer based on the given geometry, data and style.
SkyDensityPlotter.SkyDenseStyle	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.
static int	getPixelLevel(SkySurface surface) Calculates the HEALPix level whose pixels are of approximately the same size as the screen pixels for a given SkySurface.
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(SkyDensityPlotter.SkyDenseStyle 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.
static double	vectorSeparation(double[] p1, double[] p2) Angle in radians between two (not necessarily unit) vectors.

Methods inherited from class java.lang.Object

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

Field Detail

TILESIZE_REPKEY

public static final ReportKey<Double> TILESIZE_REPKEY

Report key for HEALPix tile area in square degrees.

TRANSPARENCY_KEY

public static final ConfigKey<Double> TRANSPARENCY_KEY

Config key for transparency.

COMBINER_KEY

public static final ConfigKey<Combiner> COMBINER_KEY

Config key for combination mode.

ANGLE_KEY

public static final PerUnitConfigKey<SolidAngleUnit> ANGLE_KEY

Config key for solid angle units.

Constructor Detail

SkyDensityPlotter

public SkyDensityPlotter(boolean transparent,
                         boolean hasWeight)

Constructor.

Parameters:

transparent - if true, there will be a config option for setting the alpha value of the whole layer

hasWeight - if true, an optional weight coordinate will be solicited alongside the positional coordinates

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<SkyDensityPlotter.SkyDenseStyle>

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<SkyDensityPlotter.SkyDenseStyle>

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<SkyDensityPlotter.SkyDenseStyle>

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<SkyDensityPlotter.SkyDenseStyle>

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<SkyDensityPlotter.SkyDenseStyle>

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<SkyDensityPlotter.SkyDenseStyle>

Returns:

keys used when creating a style for this plotter.

createStyle

public SkyDensityPlotter.SkyDenseStyle 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<SkyDensityPlotter.SkyDenseStyle>

Parameters:

config - map of style configuration items

Returns:

plotter-specific plot style

getRangeStyleKey

public Object getRangeStyleKey(SkyDensityPlotter.SkyDenseStyle 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<SkyDensityPlotter.SkyDenseStyle>

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,
                             SkyDensityPlotter.SkyDenseStyle 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<SkyDensityPlotter.SkyDenseStyle>

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

getPixelLevel

public static int getPixelLevel(SkySurface surface)

Calculates the HEALPix level whose pixels are of approximately the same size as the screen pixels for a given SkySurface. There is not an exact correspondance here. An attempt is made to return the result for the "largest" screen pixel (the one covering more of the sky than any other).

Parameters:

surface - plot surface

Returns:

approximately corresponding HEALPix level

vectorSeparation

public static double vectorSeparation(double[] p1,
                                      double[] p2)

Angle in radians between two (not necessarily unit) vectors. The code follows that of SLA_SEPV from SLALIB. The straightforward thing to do would just be to use the cosine rule, but that may suffer numeric instabilities for small angles, so this more complicated approach is more robust.

Parameters:

p1 - first input vector

p2 - second input vector

Returns:

angle between p1 and p2 in radians