Class Polyconic

  • All Implemented Interfaces:
    Serializable, Parameterized, Lenient­Comparable, Math­Transform, Math­Transform2D

    public class Polyconic
    extends NormalizedProjection
    American Polyconic projection (EPSG codes 9818). This projection has the following properties:
    • Neither conformal nor equal-area.
    • Parallels of latitude (except for Equator) are arcs of circles, but are not concentrics.
    • Central Meridian and Equator are straight lines; all other meridians are complex curves.
    • Scale is true along each parallel and along the central meridian, but no parallel is "standard".
    • Free of distortion only along the central meridian.


    • John P. Snyder (Map Projections - A Working Manual,
      U.S. Geological Survey Professional Paper 1395, 1987)
    • "Coordinate Conversions and Transformations including Formulas",
      EPSG Guidance Note Number 7.
    See Also:
    Serialized Form

    Defined in the sis-referencing module

    • Constructor Detail

      • Polyconic

        public Polyconic​(OperationMethod method,
                         Parameters parameters)
        Creates a Polyconic projection from the given parameters. The method argument can be the description of one of the following:
        • "American Polyconic".
        method - description of the projection parameters.
        parameters - the parameter values of the projection to create.
    • Method Detail

      • inverseTransform

        protected void inverseTransform​(double[] srcPts,
                                        int srcOff,
                                        double[] dstPts,
                                        int dstOff)
                                 throws ProjectionException
        Transforms the specified (x,y) coordinates and stores the result in dst­Pts (angles in radians).
        Specified by:
        inverse­Transform in class Normalized­Projection
        src­Pts - the array containing the source point coordinate, as linear distance on a unit sphere or ellipse.
        src­Off - the offset of the point to be converted in the source array.
        dst­Pts - the array into which the converted point coordinate is returned (may be the same than src­Pts). Coordinates will be (longitude, latitude) angles in radians.
        dst­Off - the offset of the location of the converted point that is stored in the destination array.
        Projection­Exception - if the coordinates can not be converted.