Changed default number of cascade levels to 6 everywhere in the proje…

…ct (#387)

* Changed default number of cascade levels to 6 everywhere in the project

* Ran black on sseps.py

* Added some documentation to why 6 is the default: referred to the issue on GitHub

examples/anvil_nowcast.py

@@ -99,7 +99,7 @@
  np.array([0.5]), metadata, threshold=0.1, zerovalue=-15.0
 )
 forecast_sprog = sprog.forecast(
- rainrate_field_db[-3:], velocity, 3, n_cascade_levels=8, R_thr=rainrate_thr[0]
+ rainrate_field_db[-3:], velocity, 3, n_cascade_levels=6, R_thr=rainrate_thr[0]
 )
 forecast_sprog, _ = transformation.dB_transform(
  forecast_sprog, threshold=-10.0, inverse=True

pysteps/blending/clim.py

@@ -22,7 +22,7 @@
 import numpy as np
 
 
-def get_default_skill(n_cascade_levels=8, n_models=1):
+def get_default_skill(n_cascade_levels=6, n_models=1):
  """
  Get the default climatological skill values as given in :cite:`BPS2006`.
  Take subset of n_cascade_levels or add entries with small values (1e-4) if
@@ -31,7 +31,7 @@ def get_default_skill(n_cascade_levels=8, n_models=1):
  Parameters
  ----------
  n_cascade_levels: int, optional
- Number of cascade levels. Defaults to 8.
+ Number of cascade levels. Defaults to 6, see issue #385 on GitHub.
  n_models: int, optional
  Number of NWP models. Defaults to 1.
 
@@ -157,7 +157,7 @@ def save_skill(
 
 def calc_clim_skill(
  outdir_path,
- n_cascade_levels=8,
+ n_cascade_levels=6,
  n_models=1,
  window_length=30,
 ):
@@ -168,7 +168,7 @@ def calc_clim_skill(
  Parameters
  ----------
  n_cascade_levels: int, optional
- Number of cascade levels.
+ Number of cascade levels. Defaults to 6, see issue #385 on GitHub.
  outdir_path: string
  Path to folder where the historical skill are stored. Defaults to
  path_workdir from rcparams.

pysteps/blending/steps.py

@@ -74,7 +74,7 @@ def forecast(
  timestep,
  issuetime,
  n_ens_members,
- n_cascade_levels=8,
+ n_cascade_levels=6,
  blend_nwp_members=False,
  precip_thr=None,
  norain_thr=0.0,
@@ -153,8 +153,8 @@ def forecast(
  equal to or larger than the number of NWP ensemble members / number of
  NWP models.
  n_cascade_levels: int, optional
- The number of cascade levels to use. Default set to 8 due to default
- climatological skill values on 8 levels.
+ The number of cascade levels to use. Defaults to 6,
+ see issue #385 on GitHub.
  blend_nwp_members: bool
  Check if NWP models/members should be used individually, or if all of
  them are blended together per nowcast ensemble member. Standard set to

pysteps/nowcasts/anvil.py

@@ -39,7 +39,7 @@ def forecast(
  velocity,
  timesteps,
  rainrate=None,
- n_cascade_levels=8,
+ n_cascade_levels=6,
  extrap_method="semilagrangian",
  ar_order=2,
  ar_window_radius=50,
@@ -86,7 +86,8 @@ def forecast(
  field. If set to None, no R(VIL) conversion is done and the outputs
  are in the same units as the inputs.
  n_cascade_levels: int, optional
- The number of cascade levels to use.
+ The number of cascade levels to use. Defaults to 6, see issue #385
+ on GitHub.
  extrap_method: str, optional
  Name of the extrapolation method to use. See the documentation of
  pysteps.extrapolation.interface.

pysteps/nowcasts/sprog.py

@@ -71,7 +71,8 @@ def forecast(
  precip_thr: float, required
  The threshold value for minimum observable precipitation intensity.
  n_cascade_levels: int, optional
- The number of cascade levels to use.
+ The number of cascade levels to use. Defaults to 6, see issue #385
+ on GitHub.
  extrap_method: str, optional
  Name of the extrapolation method to use. See the documentation of
  pysteps.extrapolation.interface.

pysteps/nowcasts/sseps.py

@@ -104,7 +104,8 @@ def forecast(
  n_ens_members: int
  The number of ensemble members to generate.
  n_cascade_levels: int
- The number of cascade levels to use.
+ The number of cascade levels to use. Defaults to 6, see issue #385
+ on GitHub.
  extrap_method: {'semilagrangian'}
  Name of the extrapolation method to use. See the documentation of
  pysteps.extrapolation.interface.

pysteps/nowcasts/steps.py

@@ -87,7 +87,8 @@ def forecast(
  n_ens_members: int, optional
  The number of ensemble members to generate.
  n_cascade_levels: int, optional
- The number of cascade levels to use.
+ The number of cascade levels to use. Defaults to 6, see issue #385
+ on GitHub.
  precip_thr: float, optional
  Specifies the threshold value for minimum observable precipitation
  intensity. Required if mask_method is not None or conditional is True.