refine lr schedule & download message (#2921)

configs/ssd/_base_/optimizer_120e.yml

@@ -5,7 +5,7 @@ LearningRate:
   schedulers:
   - !PiecewiseDecay
     milestones: [40, 60, 80, 100]
-    values: [0.001, 0.0005, 0.00025, 0.0001, 0.00001]
+    gamma: [0.5, 0.5, 0.4, 0.1]
     use_warmup: false
 
 OptimizerBuilder:

ppdet/optimizer.py

@@ -113,7 +113,7 @@ class PiecewiseDecay(object):
             return optimizer.lr.PiecewiseDecay(boundary, self.values)
 
         # value is computed by self.gamma
-        if value is not None:
+        value = value if value is not None else [base_lr]
         for i in self.gamma:
             value.append(base_lr * i)
 

ppdet/utils/download.py

@@ -293,14 +293,14 @@ def _dataset_exists(path, annotation, image_dir):
     Check if user define dataset exists
     """
     if not osp.exists(path):
-        logger.debug("Config dataset_dir {} is not exits, "
+        logger.warning("Config dataset_dir {} is not exits, "
                        "dataset config is not valid".format(path))
         return False
 
     if annotation:
         annotation_path = osp.join(path, annotation)
         if not osp.isfile(annotation_path):
-            logger.debug("Config annotation {} is not a "
+            logger.warning("Config annotation {} is not a "
                            "file, dataset config is not "
                            "valid".format(annotation_path))
             return False