Rewrite instance noise annealing scheduler

map2map/models/instance_noise.py

@@ -6,13 +6,12 @@ class InstanceNoise:
     """
     def __init__(self, init_std):
         self.init_std = init_std
-        self.adv_loss_cum = 0
+        self.anneal = 1
         self.ln2 = log(2)
         self.batches = 1e5
 
     def std(self, adv_loss):
-        self.adv_loss_cum += adv_loss
-        anneal = 1 - self.adv_loss_cum / self.ln2 / self.batches
-        anneal = anneal if anneal > 0 else 0
-        std = anneal * self.init_std
+        self.anneal -= adv_loss / self.ln2 / self.batches
+        std = self.anneal * self.init_std
+        std = std if std > 0 else 0
         return std