def brier(fcsts, obs, fcst_percent, obs_percent):
"""
A function to compute the Brier Score.
Parameters
----------
fcsts : numpy array
Array of the number of forecasts at a given forecast percent
obs : numpy array
Array of the number of observed grid points at a given
forecast threshold
fcst_percent : numpy array
An ordered array of the forecast probabilities.
obs_percent : numpy array
The ratio of observation points to forecast points at the
corresponding forecast percent (fcst_percent)
Returns
-------
brier_score : float
The Brier Score
"""
reliability = components.get_reliability(fcsts, fcst_percent, obs_percent)
resolution = components.get_resolution(fcsts, obs, obs_percent)
uncertainty = components.get_uncertainty(fcsts, obs)
return reliability - resolution + uncertainty
def brier_climo(fcsts, obs, fcst_percent, obs_percent):
"""
A alternative function to compute the Brier Skill Score.
Notes
-----
A special version of 'brier' used to compute the Brier Skill Score
where the reference forecast is taken to be climatology
Parameters
----------
fcsts : numpy array
Array of the number of forecasts at a given forecast percent
obs : numpy array
Array of the number of observed grid points at a given
forecast threshold
fcst_percent : numpy array
An ordered array of the forecast probabilities.
obs_percent : numpy array
The ratio of observation points to forecast points at the
corresponding forecast percent (fcst_percent)
Returns
-------
brier__skill_score : float
The Brier Skill Score
"""
reliability = components.get_reliability(fcsts, fcst_percent, obs_percent)
resolution = components.get_resolution(fcsts, obs, obs_percent)
uncertainty = components.get_uncertainty(fcsts, obs)
return (resolution - reliability) / uncertainty