""" Functions for computing vegetation indices
"""
from __future__ import division
[docs]def EVI(red, nir, blue):
""" Return the Enhanced Vegetation Index for a set of np.ndarrays
EVI is calculated as:
.. math::
2.5 * \\frac{(NIR - RED)}{(NIR + C_1 * RED - C_2 * BLUE + L)}
where:
- :math:`RED` is the red band
- :math:`NIR` is the near infrared band
- :math:`BLUE` is the blue band
- :math:`C_1 = 6`
- :math:`C_2 = 7.5`
- :math:`L = 1`
Note: bands must be given in float datatype from [0, 1]
Args:
red (np.ndarray): red band
nir (np.ndarray): NIR band
blue (np.ndarray): blue band
Returns:
np.ndarray: EVI
"""
return 2.5 * (nir - red) / (nir + 6 * red - 7.5 * blue + 1)