text: """ Functions for computing vegetation indices
  """
  from __future__ import division
  
  
  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)
  