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
  • Field Details

    • 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 Details

    • 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 Details

    • 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:
    • 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