Package pygeodesy :: Module ellipsoidalKarney |
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# Module ellipsoidalKarney

Ellipsoidal geodetic (lat-/longitude) and cartesian (x/y/z) classes LatLon and Cartesian and functions areaOf and perimeterOf based on the Python implementation of Charles F. F. Karney's GeographicLib.

Here's an example usage of `ellipsoidalKarney`:

    >>> from pygeodesy.ellipsoidalKarney import LatLon
    >>> Newport_RI = LatLon(41.49008, -71.312796)
    >>> Cleveland_OH = LatLon(41.499498, -81.695391)
    >>> Newport_RI.distanceTo(Cleveland_OH)
    866,455.4329098687  # meter

You can change the ellipsoid model used by the Karney formulae as follows:

    >>> from pygeodesy import Datums
    >>> from pygeodesy.ellipsoidalKarney import LatLon
    >>> p = LatLon(0, 0, datum=Datums.OSGB36)

or by converting to anothor datum:

    >>> p = p.convertDatum(Datums.OSGB36)

Version: 18.10.12

Classes
| LatLon An ellipsoidal LatLon similar to ellipsoidalVincenty.LatLon but using Charles F. F. Karney's Python GeographicLib to compute the geodesic distance, initial and final bearing (azimuths) between two given points or the destination point given a start point and an initial bearing.
| Cartesian Extended to convert (geocentric) Cartesian points to Karney-based (ellipsoidal) geodetic LatLon.

Functions
ispolar(points, wrap=False) Check whether a polygon encloses a pole. |
areaOf(points, datum=Datum(name='WGS84', ellipsoid=Ellipsoids.WGS84, transform=Tran`...`, wrap=True) Compute the area of a polygon. |
perimeterOf(points, closed=False, datum=Datum(name='WGS84', ellipsoid=Ellipsoids.WGS84, transform=Tran`...`, wrap=True) Compute the perimeter of a polygon. |

Function Details

### ispolar(points, wrap=False) |
Check whether a polygon encloses a pole. Parameters: `points` - The polygon points (`LatLon`s). `wrap` - Wrap and unroll longitudes (`bool`). Returns: `True` if a pole is enclosed by the polygon, `False` otherwise. Raises: `ValueError` - Insufficient number of points. `TypeError` - Some points are not `LatLon` or don't have `bearingTo2`, `initialBearingTo` and `finalBearingTo` methods.

### areaOf(points, datum=Datum(name='WGS84', ellipsoid=Ellipsoids.WGS84, transform=Tran`...`, wrap=True) |
Compute the area of a polygon. Parameters: `points` - The polygon points (LatLons). `datum` - Optional datum (Datum). `wrap` - Wrap and unroll longitudes (`bool`). Returns: Area (`meter`, same as units of the datum ellipsoid, squared). Raises: `ImportError` - Package GeographicLib missing. `TypeError` - Some points are not LatLon. `ValueError` - Insufficient number of points or longitudes not wrapped, unrolled, wrap is `False`. Note: This function requires installation of the GeographicLib package. See Also: pygeodesy.areaOf, sphericalNvector.areaOf and sphericalTrigonometry.areaOf.

### perimeterOf(points, closed=False, datum=Datum(name='WGS84', ellipsoid=Ellipsoids.WGS84, transform=Tran`...`, wrap=True) |
Compute the perimeter of a polygon. Parameters: `points` - The polygon points (LatLons). `closed` - Optionally, close the polygon (`bool`). `datum` - Optional datum (Datum). `wrap` - Wrap and unroll longitudes (`bool`). Returns: Perimeter (`meter`, same as units of the datum ellipsoid). Raises: `ImportError` - Package GeographicLib missing. `TypeError` - Some points are not LatLon. `ValueError` - Insufficient number of points or longitudes not wrapped, unrolled, wrap is `False`. Note: This function requires installation of the GeographicLib package. See Also: pygeodesy.perimeterOf and sphericalTrigonometry.perimeterOf.