Replaced links on Blue, Rouge etc papers (#3431)

Author: vfdev-5

ignite/metrics/nlp/bleu.py

@@ -72,11 +72,11 @@ class Bleu(Metric):
 
     More details can be found in `Papineni et al. 2002`__.
 
-    __ https://www.aclweb.org/anthology/P02-1040
+    __ https://aclanthology.org/P02-1040/
 
     In addition, a review of smoothing techniques can be found in `Chen et al. 2014`__
 
-    __ https://aclanthology.org/W14-3346.pdf
+    __ https://aclanthology.org/W14-3346/
 
     - ``update`` must receive output of the form ``(y_pred, y)`` or ``{'y_pred': y_pred, 'y': y}``.
     - `y_pred` (list(list(str))) - a list of hypotheses sentences.

ignite/metrics/nlp/rouge.py

@@ -191,7 +191,7 @@ class RougeN(_BaseRouge):
 
     More details can be found in `Lin 2004`__.
 
-    __ https://www.aclweb.org/anthology/W04-1013.pdf
+    __ https://aclanthology.org/W04-1013
 
     - ``update`` must receive output of the form ``(y_pred, y)`` or ``{'y_pred': y_pred, 'y': y}``.
     - `y_pred` (list(list(str))) must be a sequence of tokens.
@@ -265,7 +265,7 @@ class RougeL(_BaseRouge):
 
     More details can be found in `Lin 2004`__.
 
-    __ https://www.aclweb.org/anthology/W04-1013.pdf
+    __ https://aclanthology.org/W04-1013
 
     - ``update`` must receive output of the form ``(y_pred, y)`` or ``{'y_pred': y_pred, 'y': y}``.
     - `y_pred` (list(list(str))) must be a sequence of tokens.
@@ -331,7 +331,7 @@ class Rouge(Metric):
 
     More details can be found in `Lin 2004`__.
 
-    __ https://www.aclweb.org/anthology/W04-1013.pdf
+    __ https://aclanthology.org/W04-1013
 
     - ``update`` must receive output of the form ``(y_pred, y)`` or ``{'y_pred': y_pred, 'y': y}``.
     - `y_pred` (list(list(str))) must be a sequence of tokens.

ignite/metrics/nlp/utils.py

@@ -63,7 +63,7 @@ def modified_precision(references: Sequence[Sequence[Any]], candidate: Any, n: i
 
     More details can be found in `Papineni et al. 2002`__.
 
-    __ https://www.aclweb.org/anthology/P02-1040.pdf
+    __ https://aclanthology.org/P02-1040
 
     Args:
         references: list of references R