Bugfix: make STEPS (blending) nowcast reproducable when the seed argu…

…ment is given (pySTEPS#346)
mpvginde · Feb 9, 2024 · ba3db09 · ba3db09
1 parent 324419e
commit ba3db09
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Showing 3 changed files with 9 additions and 5 deletions.
diff --git a/pysteps/blending/steps.py b/pysteps/blending/steps.py
@@ -514,6 +514,7 @@ def forecast(
     )
 
     # 2. Initialize the noise method
+    np.random.seed(seed)
     pp, generate_noise, noise_std_coeffs = _init_noise(
         precip,
         precip_thr,
@@ -526,6 +527,7 @@ def forecast(
         noise_stddev_adj,
         measure_time,
         num_workers,
+        seed
     )
 
     # 3. Perform the cascade decomposition for the input precip fields and
@@ -1662,6 +1664,7 @@ def _init_noise(
     noise_stddev_adj,
     measure_time,
     num_workers,
+    seed
 ):
     """Initialize the noise method."""
     if noise_method is None:
@@ -1690,6 +1693,7 @@ def _init_noise(
             20,
             conditional=True,
             num_workers=num_workers,
+            seed=seed
         )
 
         if measure_time:
@@ -1944,7 +1948,6 @@ def _init_random_generators(
     if noise_method is not None:
         randgen_prec = []
         randgen_motion = []
-        np.random.seed(seed)
         for j in range(n_ens_members):
             rs = np.random.RandomState(seed)
             randgen_prec.append(rs)

diff --git a/pysteps/noise/utils.py b/pysteps/noise/utils.py
@@ -100,18 +100,18 @@ def compute_noise_stddev_adjs(
         N_stds = []
 
     randstates = []
-    seed = None
+
     for k in range(num_iter):
         randstates.append(np.random.RandomState(seed=seed))
         seed = np.random.randint(0, high=1e9)
-
+    
     for k in range(num_iter):
 
         def worker():
             # generate Gaussian white noise field, filter it using the chosen
             # method, multiply it with the standard deviation of the observed
             # field and apply the precipitation mask
-            N = noise_generator(noise_filter, randstate=randstates[k], seed=seed)
+            N = noise_generator(noise_filter, randstate=randstates[k])
             N = N / np.std(N) * sigma + mu
             N[~MASK] = R_thr_2
 

diff --git a/pysteps/nowcasts/steps.py b/pysteps/nowcasts/steps.py
@@ -443,6 +443,7 @@ def f(precip, i):
         precip[i, ~np.isfinite(precip[i, :])] = np.nanmin(precip[i, :])
 
     if noise_method is not None:
+        np.random.seed(seed)
         # get methods for perturbations
         init_noise, generate_noise = noise.get_method(noise_method)
 
@@ -466,6 +467,7 @@ def f(precip, i):
                 20,
                 conditional=True,
                 num_workers=num_workers,
+                seed=seed
             )
 
             if measure_time:
@@ -543,7 +545,6 @@ def f(precip, i):
     if noise_method is not None:
         randgen_prec = []
         randgen_motion = []
-        np.random.seed(seed)
         for _ in range(n_ens_members):
             rs = np.random.RandomState(seed)
             randgen_prec.append(rs)