:tocdepth: 3

:py:mod:`gws.lib.crs`
=====================

.. py:module:: gws.lib.crs


**Source code:** :source:`gws.lib.crs<gws/lib/crs/__init__.py>`



Package Contents
----------------



.. py:function:: best_match(crs: gws.Crs, supported_crs: list[gws.Crs]) -> gws.Crs

   Return a crs from the list that most closely matches the given crs.

   :param crs: target CRS
   :param supported_crs: CRS list

   :returns: A CRS object


.. py:data:: COORDINATE_PRECISION_DEG
   :value: 7


.. py:data:: COORDINATE_PRECISION_M
   :value: 2


.. py:exception:: Error


   Bases: :py:obj:`gws.Error`

   Generic GWS error.


.. py:function:: get(crs_name: Optional[gws.CrsName]) -> Optional[gws.Crs]

   Returns the CRS for a given CRS-code or SRID.


.. py:class:: Object(**kwargs)


   Bases: :py:obj:`gws.Crs`

   Coordinate reference system.

   .. py:method:: axis_for_format(fmt)

      Get the axis depending on the string format.

      We adhere to the GeoServer convention here:
      https://docs.geoserver.org/latest/en/user/services/wfs/axis_order.html


   .. py:method:: extent_size_in_meters(extent)

      Calculate the width and height of an extent in meters;

      :param extent: Extent.


   .. py:method:: point_offset_in_meters(xy, dist, az)

      Calculate a point with an offset in meters.
      :param xy: Point.
      :param dist: Distance in meters.
      :param az: Azimuth in degrees (0 = North, 90 = East, etc.).


   .. py:method:: to_geojson()

      Return a geojson representation of the CRS (as per GJ2008).

      :returns: A GeoJson dict.

      .. rubric:: References

      https://geojson.org/geojson-spec#named-crs


   .. py:method:: to_string(fmt=None)

      Return a string representation of the CRS.

      :param fmt: Format to use.

      :returns: A string.


   .. py:method:: transform_extent(ext, crs_to)

      Transform an Extent from this CRS to another.

      :param extent: Extent.
      :param crs_to: Target CRS.

      :returns: A transformed Extent.


   .. py:method:: transformer(crs_to)

      Create a transformer function to another CRS.

      :param crs_to: Target CRS.

      :returns: A function.



.. py:function:: parse(crs_name: gws.CrsName) -> tuple[gws.CrsFormat, Optional[gws.Crs]]

   Parses a CRS to a tuple of CRS-format and the CRS itself.


.. py:function:: qgis_extent_width(extent: gws.Extent) -> float

.. py:function:: require(crs_name: gws.CrsName) -> gws.Crs

   Raises an error if no correct CRS is given.


.. py:data:: WEBMERCATOR

.. py:data:: WEBMERCATOR_RADIUS
   :value: 6378137


.. py:data:: WEBMERCATOR_SQUARE

.. py:data:: WGS84