Class CylindricalEqualArea

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

public class CylindricalEqualArea extends NormalizedProjection
Cylindrical Equal Area projection (EPSG codes 9834, 9835). This is the simplest equal-area projection. This projection has various names depending on its standard parallel:
Non-exhaustive list of variants
Name Standard parallel
Lambert cylindrical equal-area
Behrmann cylindrical equal-area 30°
Gall orthographic 45°
Balthasart 50°

Description

The parallels and the meridians are straight lines and cross at right angles. The scale is true along standard parallels, but distortion increase greatly at other locations. Distortions are so great that there is little use of this projection for world mapping purposes. However this projection may be useful for computing areas.
Since:
0.8
See Also:

Defined in the sis-referencing module

  • Constructor Details

    • CylindricalEqualArea

      public CylindricalEqualArea(OperationMethod method, Parameters parameters)
      Creates a Cylindrical Equal Area projection from the given parameters.
      Parameters:
      method - Description of the projection parameters.
      parameters - The parameter values of the projection to create.
  • Method Details

    • createMapProjection

      public MathTransform createMapProjection(MathTransformFactory factory) throws FactoryException
      Returns the sequence of normalizationthisdenormalization 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 later case, this transform will 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:
      Factory­Exception - if an error occurred while creating a transform.
      See Also:
    • transform

      public Matrix transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) throws ProjectionException
      Converts the specified (λ,φ) coordinate (units in radians) and stores the result in dst­Pts (linear distance on a unit sphere). In addition, opportunistically computes the projection derivative if derivate is true.
      Specified by:
      transform in class Normalized­Projection
      Parameters:
      src­Pts - the array containing the source point coordinate, as (longitude, latitude) angles in radians.
      src­Off - the offset of the single coordinate to be converted in the source array.
      dst­Pts - the array into which the converted coordinate 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 coordinate 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 coordinate can not be converted.
      See Also:
    • transform

      public void transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) throws TransformException
      Converts a list of coordinate points. This method performs the same calculation than above transform(double[], int, double[], int, boolean) method, but is overridden for efficiency.
      Specified by:
      transform in interface Math­Transform
      Overrides:
      transform in class Abstract­Math­Transform
      Parameters:
      src­Pts - the array containing the source point coordinates.
      src­Off - the offset to the first point to be transformed in the source array.
      dst­Pts - the array into which the transformed point coordinates are returned. May be the same than src­Pts.
      dst­Off - the offset to the location of the first transformed point that is stored in the destination array.
      num­Pts - the number of point objects to be transformed.
      Throws:
      Transform­Exception - if a point can not be converted.
    • inverseTransform

      protected void inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) throws ProjectionException
      Converts 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 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.
      Throws:
      Projection­Exception - if the point can not be converted.