xrspatial.terrain.generate_terrain¶
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xrspatial.terrain.generate_terrain(x_range: tuple = (0, 500), y_range: tuple = (0, 500), width: int = 25, height: int = 30, canvas: Optional[datashader.core.Canvas] = None, seed: int = 10, zfactor: int = 4000, full_extent: Optional[str] = None) → xarray.core.dataarray.DataArray[source]¶ Generates a pseudo-random terrain which can be helpful for testing raster functions
- x_range: tuple (default = (0, 500))
Range of x values.
- x_range: tuple (default = (0, 500))
Range of y values.
- width: int (default = 25)
Width of output data array in pixels.
- height: int (default = 30)
Height of output data array in pixels.
- canvas: ds.Canvas (default = None)
Instance for passing output dimensions / ranges
- seed: int (default = 10)
Seed for random number generator.
- zfactor: int (default = 4000)
Multipler for z values.
- full_extent: str, optional (default = None)
bbox<xmin, ymin, xmax, ymax>. Full extent of coordinate system.
- terrain: xarray.DataArray
2D array of generated terrain.
Algorithm References: - This was inspired by Michael McHugh’s 2016 PyCon Canada talk: # noqa
Michael McHugh, PyCon Canada, YouTube, Dec. 9, 2016, https://www.youtube.com/watch?v=O33YV4ooHSo, Accessed Apr. 22, 2021. # noqa
Patel, A, Red Blob Games, Making maps with noise functions, https://www.redblobgames.com/maps/terrain-from-noise/, Accessed Apr. 22, 2021. # noqa
Imports >>> import datashader as ds >>> from datashader.transfer_functions import shade >>> from xrspatial import generate_terrain
Create Canvas >>> cvs = ds.Canvas(plot_width=800, >>> plot_height=600, >>> x_range=(-20e6, 20e6), >>> y_range=(-20e6, 20e6))
Generate Terrain Data Array >>> terrain = generate_terrain(canvas = cvs) >>> print(terrain) <xarray.DataArray ‘terrain’ (y: 600, x: 800)> array([[0., 0., 0., …, 0., 0., 0.],
[0., 0., 0., …, 0., 0., 0.], [0., 0., 0., …, 0., 0., 0.], …, [0., 0., 0., …, 0., 0., 0.], [0., 0., 0., …, 0., 0., 0.], [0., 0., 0., …, 0., 0., 0.]])
- Coordinates:
x (x) float64 -1.998e+07 -1.992e+07 … 1.992e+07 1.997e+07
y (y) float64 -1.997e+07 -1.99e+07 -1.983e+07 … 1.99e+07 1.997e+07
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xrspatial.terrain.res¶ 1