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map.geodesy.AuthalicLatitudeConverter

Convert between geodetic and authalic latitudes

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Description

An AuthalicLatitudeConverter object provides conversion methods between geodetic and authalic latitudes for an ellipsoid with a given eccentricity.

The authalic latitude maps an ellipsoid (oblate spheroid) to a sphere while preserving surface area. Use authalic latitudes when implementing equal area map projections on the ellipsoid.

Creation

Syntax

converter = map.geodesy.AuthalicLatitudeConverter
converter = map.geodesy.AuthalicLatitudeConverter(spheroid)

Description

converter = map.geodesy.AuthalicLatitudeConverter creates an AuthalicLatitudeConverter object for a sphere and sets the Eccentricity to 0.

example

converter = map.geodesy.AuthalicLatitudeConverter(spheroid) creates an authalic latitude converter object and sets the Eccentricity property to match the specified spheroid object.

example

Input Arguments

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Reference spheroid, specified as a referenceEllipsoid object, oblateSpheroid object, or referenceSphere object. The term reference spheroid is used synonymously with reference ellipsoid. To create a reference spheroid, use the creation function for the object. To specify the reference ellipsoid for WGS84, use the wgs84Ellipsoid function.

For more information about reference spheroids, see Comparison of Reference Spheroids.

Example: spheroid = referenceEllipsoid('GRS 80');

Properties

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Ellipsoid eccentricity, specified as a numeric scalar. Eccentricity is in the interval [0, 0.5]. Eccentricities larger than 0.5 are possible in theory, but do not occur in practice and are not supported.

Data Types: double

Object Functions

forward Convert geodetic latitude to authalic, conformal, isometric, or rectifying latitude
inverse Convert authalic, conformal, isometric, or rectifying latitude to geodetic latitude

Examples

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Create a Geodetic Reference System 1980 (grs80) reference ellipsoid.

grs80 = referenceEllipsoid('GRS 80');

Create an authalic converter object and set the value of the Eccentricity property.

conv1 = map.geodesy.AuthalicLatitudeConverter;
conv1.Eccentricity = grs80.Eccentricity
conv1 = 

  AuthalicLatitudeConverter with properties:

    Eccentricity: 0.0818

Create a reference ellipsoid.

grs80 = referenceEllipsoid('GRS 80');

Create an authalic latitude converter object based on the ellipsoid.

conv2 = map.geodesy.AuthalicLatitudeConverter(grs80)
conv1 = 

  AuthalicLatitudeConverter with properties:

    Eccentricity: 0.0818

Version History

Introduced in R2013a

See Also

Functions

Objects