add flag for surface interpolation bias correction

sup3r/models/surface.py

@@ -43,7 +43,7 @@ class SurfaceSpatialMetModel(AbstractInterface):
 
  def __init__(self, features, s_enhance, noise_adders=None,
  temp_lapse=None, w_delta_temp=None, w_delta_topo=None,
- pres_div=None, pres_exp=None):
+ pres_div=None, pres_exp=None, fix_bias=True):
  """
  Parameters
  ----------
@@ -85,6 +85,10 @@ def __init__(self, features, s_enhance, noise_adders=None,
  pres_div : None | float
  Exponential factor in the pressure scale height equation. Defaults
  to the cls.PRES_EXP attribute.
+ fix_bias : bool
+ Some local bias can be introduced by the bilinear interp + lapse
+ rate, this flag will attempt to correct that bias by using the
+ low-resolution deviation from the input data
  """
 
  self._features = features
@@ -95,6 +99,7 @@ def __init__(self, features, s_enhance, noise_adders=None,
  self._w_delta_topo = w_delta_topo or self.W_DELTA_TOPO
  self._pres_div = pres_div or self.PRES_DIV
  self._pres_exp = pres_exp or self.PRES_EXP
+ self._fix_bias = fix_bias
 
  if isinstance(self._noise_adders, (int, float)):
  self._noise_adders = [self._noise_adders] * len(self._features)
@@ -317,7 +322,10 @@ def downscale_temp(self, single_lr_temp, topo_lr, topo_hr):
  lower_data = single_lr_temp.copy() + topo_lr * self._temp_lapse
  hi_res_temp = self.downscale_arr(lower_data, self._s_enhance)
  hi_res_temp -= topo_hr * self._temp_lapse
- hi_res_temp = self._fix_downscaled_bias(single_lr_temp, hi_res_temp)
+
+ if self._fix_bias:
+ hi_res_temp = self._fix_downscaled_bias(single_lr_temp,
+ hi_res_temp)
 
  return hi_res_temp
 
@@ -379,7 +387,8 @@ def downscale_rh(self, single_lr_rh, single_lr_temp, single_hr_temp,
  + self._w_delta_temp * delta_temp
  + self._w_delta_topo * delta_topo)
 
- hi_res_rh = self._fix_downscaled_bias(single_lr_rh, hi_res_rh)
+ if self._fix_bias:
+ hi_res_rh = self._fix_downscaled_bias(single_lr_rh, hi_res_rh)
 
  return hi_res_rh
 
@@ -437,7 +446,9 @@ def downscale_pres(self, single_lr_pres, topo_lr, topo_hr):
  const = 101325 * (1 - (1 - topo_hr / self._pres_div)**self._pres_exp)
  hi_res_pres -= const
 
- hi_res_pres = self._fix_downscaled_bias(single_lr_pres, hi_res_pres)
+ if self._fix_bias:
+ hi_res_pres = self._fix_downscaled_bias(single_lr_pres,
+ hi_res_pres)
 
  if np.min(hi_res_pres) < 0.0:
  msg = ('Spatial interpolation of surface pressure '