xrspatial.zonal.trim¶
- xrspatial.zonal.trim(raster: xarray.core.dataarray.DataArray, values: Union[list, tuple] = (nan,), name: str = 'trim') xarray.core.dataarray.DataArray[source]¶
Trim scans from the edges and eliminates rows / cols which only contain the values supplied.
- Parameters
raster (xr.DataArray) –
values (list or tuple, default=(np.nan)) – List of zone ids to trim from raster edge.
name (str, default='trim') – Output xr.DataArray.name property.
- Returns
trim_agg
- Return type
xarray.DataArray
Notes
This operation will change the output size of the raster.
Examples
import matplotlib.pyplot as plt import numpy as np import xarray as xr from xrspatial import generate_terrain from xrspatial.zonal import trim # Generate Example Terrain W = 500 H = 300 template_terrain = xr.DataArray(np.zeros((H, W))) x_range=(-20e6, 20e6) y_range=(-20e6, 20e6) terrain_agg = generate_terrain( template_terrain, x_range=x_range, y_range=y_range ) # Edit Attributes terrain_agg = terrain_agg.assign_attrs( { 'Description': 'Example Terrain', 'units': 'km', 'Max Elevation': '4000', } ) terrain_agg = terrain_agg.rename({'x': 'lon', 'y': 'lat'}) terrain_agg = terrain_agg.rename('Elevation') terrain_agg = terrain_agg.astype('int') # Trim Image trimmed_agg = trim(raster = terrain_agg, values = [0]) # Edit Attributes trimmed_agg = trimmed_agg.assign_attrs({'Description': 'Example Trim'}) # Plot Terrain terrain_agg.plot(cmap = 'terrain', aspect = 2, size = 4) plt.title("Terrain") plt.ylabel("latitude") plt.xlabel("longitude") # Plot Trimmed Terrain trimmed_agg.plot(cmap = 'terrain', aspect = 2, size = 4) plt.title("Trim") plt.ylabel("latitude") plt.xlabel("longitude")
>>> print(terrain_agg.shape) (300, 500) >>> print(terrain_agg.attrs) { 'res': (80000.0, 133333.3333333333), 'Description': 'Example Terrain', 'units': 'km', 'Max Elevation': '4000', } >>> print(trimmed_agg.shape) (268, 500) >>> print(trimmed_agg.attrs) { 'res': (80000.0, 133333.3333333333), 'Description': 'Example Trim', 'units': 'km', 'Max Elevation': '4000', }
