xrspatial.multispectral.evi¶
- xrspatial.multispectral.evi(nir_agg: xarray.core.dataarray.DataArray, red_agg: xarray.core.dataarray.DataArray, blue_agg: xarray.core.dataarray.DataArray, c1=6.0, c2=7.5, soil_factor=1.0, gain=2.5, name='evi')[source]¶
Computes Enhanced Vegetation Index. Allows for importved sensitivity in high biomass regions, de-coupling of the canopy background signal and reduction of atmospheric influences.
- Parameters
nir_agg (xr.DataArray) – 2D array of near-infrared band data.
red_agg (xr.DataArray) – 2D array of red band data.
blue_agg (xr.DataArray) – 2D array of blue band data.
c1 (float, default=6.0) – First coefficient of the aerosol resistance term.
c2 (float, default=7.5) – Second coefficients of the aerosol resistance term.
soil_factor (float, default=1.0) – Soil adjustment factor between -1.0 and 1.0.
gain (float, default=2.5) – Amplitude adjustment factor.
name (str, default='evi') – Name of output DataArray.
- Returns
evi_agg – 2D array of evi values. All other input attributes are preserved.
- Return type
xarray.DataArray of same type as inputs
References
Examples
import matplotlib.pyplot as plt from xrspatial.multispectral import evi from xrspatial.datasets import get_data # Open Example Data data = get_data('sentinel-2') nir = data['NIR'] red = data['Red'] blue = data['Blue'] # Generate EVI Aggregate Array evi_agg = evi(nir_agg = nir, red_agg = red, blue_agg =blue) # Plot NIR Band nir.plot(cmap = 'Greys', aspect = 2, size = 4) plt.title("NIR Band") plt.ylabel("latitude") plt.xlabel("longitude") # Plot Red Band red.plot(cmap = 'Greys', aspect = 2, size = 4) plt.title("Red Band") plt.ylabel("latitude") plt.xlabel("longitude") # Plot Blue Band blue.plot(cmap = 'Greys', aspect = 2, size = 4) plt.title("Blue Band") plt.ylabel("latitude") plt.xlabel("longitude") # Plot EVI evi_agg.plot(cmap = 'Greys', aspect = 2, size = 4) plt.title("EVI") plt.ylabel("latitude") plt.xlabel("longitude")
>>> print(evi_agg[100:103, 100: 102]) <xarray.DataArray 'evi' (y: 3, x: 2)> array([[-3.8247012 , -9.51086957], [11.81818182, 3.83783784], [-8.53211009, 5.48672566]]) Coordinates: * x (x) float64 6.01e+05 6.01e+05 * y (y) float64 4.699e+06 4.699e+06 4.699e+06 band int32 ... Attributes: (12/13) transform: [ 1.00000e+01 0.00000e+00 6.00000e+05 0.0000... # noqa crs: +init=epsg:32719 res: [10. 10.] is_tiled: 1 nodatavals: nan scales: 1.0 ... ... instrument: Sentinel-2 Band: 07 Name: NIR Bandwidth (µm): 115 Nominal Wavelength (µm): 0.842 Resolution (m): 10
