minor fix, update docs, and modify the epoch number to count from 1 in the pruned_transducer_stateless4/decode.py

egs/librispeech/ASR/pruned_transducer_stateless4/decode.py

@@ -18,16 +18,16 @@
 """
 Usage:
 (1) greedy search
-./pruned_transducer_stateless2/decode.py \
-        --epoch 28 \
+./pruned_transducer_stateless4/decode.py \
+        --epoch 30 \
         --avg 15 \
         --exp-dir ./pruned_transducer_stateless2/exp \
         --max-duration 100 \
         --decoding-method greedy_search
 
 (2) beam search
-./pruned_transducer_stateless2/decode.py \
-        --epoch 28 \
+./pruned_transducer_stateless4/decode.py \
+        --epoch 30 \
         --avg 15 \
         --exp-dir ./pruned_transducer_stateless2/exp \
         --max-duration 100 \
@@ -35,8 +35,8 @@ Usage:
         --beam-size 4
 
 (3) modified beam search
-./pruned_transducer_stateless2/decode.py \
-        --epoch 28 \
+./pruned_transducer_stateless4/decode.py \
+        --epoch 30 \
         --avg 15 \
         --exp-dir ./pruned_transducer_stateless2/exp \
         --max-duration 100 \
@@ -44,8 +44,8 @@ Usage:
         --beam-size 4
 
 (4) fast beam search
-./pruned_transducer_stateless2/decode.py \
-        --epoch 28 \
+./pruned_transducer_stateless4/decode.py \
+        --epoch 30 \
         --avg 15 \
         --exp-dir ./pruned_transducer_stateless2/exp \
         --max-duration 1500 \
@@ -99,9 +99,9 @@ def get_parser():
     parser.add_argument(
         "--epoch",
         type=int,
-        default=28,
+        default=30,
         help="""It specifies the checkpoint to use for decoding.
-        Note: Epoch counts from 0.
+        Note: Epoch counts from 1.
         You can specify --avg to use more checkpoints for model averaging.""",
     )
 
@@ -128,13 +128,17 @@ def get_parser():
         "--use-averaged-model",
         type=str2bool,
         default=False,
-        help="Whether to load averaged model",
+        help="Whether to load averaged model. Currently it only supports "
+        "using --epoch. If True, it would decode with the averaged model "
+        "over the epoch range from `epoch-avg` (excluded) to `epoch`."
+        "Actually only the models with epoch number of `epoch-avg` and "
+        "`epoch` are loaded for averaging. ",
     )
 
     parser.add_argument(
         "--exp-dir",
         type=str,
-        default="pruned_transducer_stateless2/exp",
+        default="pruned_transducer_stateless4/exp",
         help="The experiment dir",
     )
 
@@ -529,19 +533,20 @@ def main():
             start = params.epoch - params.avg + 1
             filenames = []
             for i in range(start, params.epoch + 1):
-                if start >= 0:
+                if i >= 1:
                     filenames.append(f"{params.exp_dir}/epoch-{i}.pt")
             logging.info(f"averaging {filenames}")
             model.to(device)
             model.load_state_dict(average_checkpoints(filenames, device=device))
     else:
-        assert params.iter == 0
+        assert params.iter == 0 and params.avg > 0
         start = params.epoch - params.avg
+        assert start >= 1
         filename_start = f"{params.exp_dir}/epoch-{start}.pt"
         filename_end = f"{params.exp_dir}/epoch-{params.epoch}.pt"
         logging.info(
-            f"averaging modes over range with {filename_start} (excluded) "
-            f"and {filename_end}"
+            f"Calculating the averaged model over epoch range from "
+            f"{start} (excluded) to {params.epoch}"
         )
         model.to(device)
         model.load_state_dict(