Change wrong word

deepmd_pt/utils/learning_rate.py

@@ -37,7 +37,7 @@ def value(self, step):
 class LearningRatePolynomial(object):
 
     def __init__(self, start_lr, stop_lr, stop_steps, **kwargs):
-        """Construct an exponential-decayed learning rate.
+        """Construct an polynomial-decayed learning rate.
 
         Args:
         - start_lr: Initial learning rate.