com.vividsolutions.jts.algorithm

Class MinimumBoundingCircle


  • public class MinimumBoundingCircle
extends Object
    Computes the Minimum Bounding Circle (MBC) for the points in a Geometry. The MBC is the smallest circle which covers all the input points (this is also known as the Smallest Enclosing Circle). This is equivalent to computing the Maximum Diameter of the input point set.

    The computed circle can be specified in two equivalent ways, both of which are provide as output by this class:

    • As a centre point and a radius
    • By the set of points defining the circle. Depending on the number of points in the input and their relative positions, this will be specified by anywhere from 0 to 3 points.
      • 0 or 1 points indicate an empty or trivial input point arrangement.
      • 2 or 3 points define a circle which contains all the input points.
    The class can also output a Geometry which approximates the shape of the MBC (although as an approximation it is not guaranteed to cover all the input points.)
    See Also:
    MinimumDiameter

    • Constructor Detail

      • MinimumBoundingCircle

        public MinimumBoundingCircle(Geometry geom)
        Creates a new object for computing the minimum bounding circle for the point set defined by the vertices of the given geometry.
        Parameters:
        geom - the geometry to use to obtain the point set

    • Method Detail

      • getCircle

        public Geometry getCircle()
        Gets a geometry which represents the Minimum Bounding Circle. If the input is degenerate (empty or a single unique point), this method will return an empty geometry or a single Point geometry. Otherwise, a Polygon will be returned which approximates the Minimum Bounding Circle. (Note that because the computed polygon is only an approximation, it may not precisely contain all the input points.)
        Returns:
        a Geometry representing the Minimum Bounding Circle.

      • getFarthestPoints

        public Geometry getFarthestPoints()
        Gets a geometry representing a line between the two farthest points in the input. These points will be two of the extremal points of the Minimum Bounding Circle. They also lie on the convex hull of the input.
        Returns:
        a LineString between the two farthest points of the input

      • getDiameter

        public Geometry getDiameter()
        Gets a geometry representing the diameter of the computed Minimum Bounding Circle.
        Returns:
        the diameter LineString of the Minimum Bounding Circle

      • getExtremalPoints

        public Coordinate[] getExtremalPoints()
        Gets the extremal points which define the computed Minimum Bounding Circle. There may be zero, one, two or three of these points, depending on the number of points in the input and the geometry of those points.
        Returns:
        the points defining the Minimum Bounding Circle

      • getCentre

        public Coordinate getCentre()
        Gets the centre point of the computed Minimum Bounding Circle.
        Returns:
        the centre point of the Minimum Bounding Circle

      • getRadius

        public double getRadius()
        Gets the radius of the computed Minimum Bounding Circle.
        Returns:
        the radius of the Minimum Bounding Circle