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104 lines
3.4 KiB
Python
104 lines
3.4 KiB
Python
"""A wrapper for Projections."""
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from typing import Any, Dict, Optional, Sequence, Union
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from ee import apifunction
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from ee import computedobject
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class Projection(computedobject.ComputedObject):
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"""An object to represent an Earth Engine Projection.
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Examples:
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# Construct a variety of projections.
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# crs: EPSG:4326, transform: identity
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ee.Projection('EPSG:4326')
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# crs: EPSG:4326, transform: projection.scale(2, 3)
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ee.Projection('EPSG:4326', [2, 0, 0, 0, 3, 0])
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# crs: EPSG:4326, transform wkt:
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ee.Projection(
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'EPSG:4326',
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transformWkt=(
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'GEOGCS["WGS 84",'
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' DATUM["WGS_1984",'
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' SPHEROID["WGS 84",6378137,298.257223563,'
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' AUTHORITY["EPSG","7030"]],'
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' AUTHORITY["EPSG","6326"]],'
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' PRIMEM["Greenwich",0,'
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' AUTHORITY["EPSG","8901"]],'
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' UNIT["degree",0.0174532925199433,'
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' AUTHORITY["EPSG","9122"]],'
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' AXIS["Longitude",EAST],'
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' AXIS["Latitude",NORTH]]'
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),
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)
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"""
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_initialized: bool = False
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def __init__(
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self,
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crs: Union[str, computedobject.ComputedObject],
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transform: Optional[
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Union[Sequence[float], computedobject.ComputedObject]
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] = None,
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# pylint: disable-next=invalid-name
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transformWkt: Optional[Union[str, computedobject.ComputedObject]] = None,
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):
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"""Creates a Projection wrapper.
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Returns a Projection with the given base coordinate system and the given
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transform between projected coordinates and the base.
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Args:
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crs: The base coordinate reference system of this Projection, given as a
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well-known authority code (e.g. 'EPSG:4326') or a WKT string.
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transform: The transform between projected coordinates and the base
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coordinate system, specified as a 2x3 affine transform matrix in
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row-major order: [xScale, xShearing, xTranslation, yShearing, yScale,
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yTranslation]. May not specify both this and 'transformWkt'.
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transformWkt: The transform between projected coordinates and the base
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coordinate system, specified as a WKT string. May not specify both this
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and 'transform'.
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"""
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self.initialize()
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if (
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isinstance(crs, computedobject.ComputedObject)
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and transform is None
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and transformWkt is None
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):
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# Handles cases where a user wants to manually cast a projection. Examples
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# include: `ee.Projection(ee.Image(...).projection())` and
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# `ee.Projection(ee.Projection(...))`.
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if self.is_func_returning_same(crs):
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# If it is a call that is already returning a Projection, just cast.
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super().__init__(crs.func, crs.args, crs.varName)
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return
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args: Dict[str, Any] = {'crs': crs}
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if transform is not None:
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args['transform'] = transform
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if transformWkt is not None:
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args['transformWkt'] = transformWkt
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func = apifunction.ApiFunction(self.name())
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super().__init__(func, func.promoteArgs(args))
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@classmethod
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def initialize(cls) -> None:
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"""Imports API functions to this class."""
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if not cls._initialized:
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apifunction.ApiFunction.importApi(cls, cls.name(), cls.name())
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cls._initialized = True
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@classmethod
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def reset(cls) -> None:
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"""Removes imported API functions from this class."""
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apifunction.ApiFunction.clearApi(cls)
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cls._initialized = False
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@staticmethod
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def name() -> str:
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return 'Projection'
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