Package org.apache.sis.referencing.operation.projection

Class Polyconic

java.lang.Object
org.apache.sis.io.wkt.FormattableObject
org.apache.sis.referencing.operation.transform.AbstractMathTransform
org.apache.sis.referencing.operation.transform.AbstractMathTransform2D
org.apache.sis.referencing.operation.projection.NormalizedProjection
org.apache.sis.referencing.operation.projection.Polyconic
All Implemented Interfaces:
Serializable, Parameterized, LenientComparable, org.opengis.referencing.operation.MathTransform, org.opengis.referencing.operation.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.

References

  • 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.
Since:
1.0
Version:
1.0
Author:
Simon Reynard (Geomatys), Martin Desruisseaux (Geomatys), Rémi Maréchal (Geomatys)
See Also:

  • Constructor Details

    • Polyconic

      public Polyconic(org.opengis.referencing.operation.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".
      Parameters:
      method - description of the projection parameters.
      parameters - the parameter values of the projection to create.

  • Method Details

    • createMapProjection

      public org.opengis.referencing.operation.MathTransform createMapProjection(org.opengis.referencing.operation.MathTransformFactory factory) throws org.opengis.util.FactoryException
      Returns the sequence of normalization → this → denormalization transforms as a whole. The transform returned by this method expects (longitude, latitude) coordinates in degrees and returns (x,y) coordinates in metres.

      The non-linear part of the returned transform will be this transform, except if the ellipsoid is spherical. In the latter case, this transform may be replaced by a simplified implementation.

      Overrides:
      createMapProjection in class NormalizedProjection
      Parameters:
      factory - the factory to use for creating the transform.
      Returns:
      the map projection from (λ,φ) to (x,y) coordinates.
      Throws:
      org.opengis.util.FactoryException - if an error occurred while creating a transform.
      See Also:

    • transform

      public org.opengis.referencing.operation.Matrix transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) throws ProjectionException
      Projects the specified (λ,φ) coordinates (units in radians) and stores the result in dstPts. In addition, opportunistically computes the projection derivative if derivate is true. The results must be multiplied by the denormalization matrix before to get linear distances.
      Specified by:
      transform in class NormalizedProjection
      Parameters:
      srcPts - the array containing the source point coordinates, as (longitude, latitude) angles in radians.
      srcOff - the offset of the single coordinate tuple to be converted in the source array.
      dstPts - the array into which the converted coordinates is returned (may be the same than srcPts). Coordinates will be expressed in a dimensionless unit, as a linear distance on a unit sphere or ellipse.
      dstOff - the offset of the location of the converted coordinates that is stored in the destination array.
      derivate - true for computing the derivative, or false if not needed.
      Returns:
      the matrix of the projection derivative at the given source position, or null if the derivate argument is false.
      Throws:
      ProjectionException - if the coordinates cannot be converted.
      See Also:

    • 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
      Parameters:
      srcPts - the array containing the source point coordinates, 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 coordinates 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.
      Throws:
      ProjectionException - if the coordinates cannot be converted.