Class XYArrayPlacement

java.lang.Object
uk.ac.starlink.ttools.plot2.layer.XYArrayPlacement

@Equality public abstract class XYArrayPlacement extends Object
Defines how to map an XYArrayData object to a definite position in data space.
Since:
18 Aug 2022
Author:
Mark Taylor
  • Field Details

    • INDEX

      public static final XYArrayPlacement INDEX
      Uses X,Y position at indicated fraction through arrays.
    • XMAX

      public static final XYArrayPlacement XMAX
      Uses the position with the maximal X value.
    • XMIN

      public static final XYArrayPlacement XMIN
      Uses the position with the minimal X value.
    • YMAX

      public static final XYArrayPlacement YMAX
      Uses the position with the maximal Y value.
    • YMIN

      public static final XYArrayPlacement YMIN
      Uses the position with the minimal Y value.
    • XYMEAN

      public static final XYArrayPlacement XYMEAN
      Uses the center of gravity of all the (X,Y) values.
  • Constructor Details

    • XYArrayPlacement

      protected XYArrayPlacement(String name, String description, boolean usesFraction)
      Constructor.
      Parameters:
      name - short name for presentation to users
      description - XML-friendly description of behaviour
      usesFraction - true iff this placement pays any attention to the value of the fraction parameter
  • Method Details

    • getName

      public String getName()
      Returns this placement policy's name.
      Returns:
      name
    • getDescription

      public String getDescription()
      Returns this placement policy's description.
      Returns:
      XML-friendly description text
    • usesFraction

      public boolean usesFraction()
      Indicates whether this placement pays attention to the value of the fraction parameter.
      Returns:
      true if fraction may influence placement, false if it definitely doesn't
    • readPosition

      public abstract boolean readPosition(XYArrayData xyData, double fraction, double[] dpos)
      Attempts to determine the reference position of an XYArrayData object. On success, the position in data coordinates is written into the supplied 2-element array.
      Parameters:
      xyData - XY data, not null
      fraction - numeric value in the range 0..1; may or may not be used
      dpos - 2-element array for X, Y output on success
      Returns:
      true for success
    • toString

      public String toString()
      Overrides:
      toString in class Object