Ticket #11314: trac_11314-tableau-from-shape-and-word-ht.patch

sage/combinat/tableau.py

@@ -1676 +1676 @@
                 res[j][k] = i -1
     return Tableau_class(res)
 
-def from_shape_and_word(shape, w):
-    """
-    Returns a tableau from a shape and word.
+def from_shape_and_word(shape, w, french=True):
+    r"""
+    Returns a tableau from a shape and word.  
+
+    INPUT:
     
+    - ``shape`` -- a partition
+    - ``w`` -- a word whose length equals that of the partition
+    - ``french`` -- boolean
+
+    OUTPUT: 
+
+    A tableau, whose shape is ``shape`` and whose reading word is ``w``.  
+    If ``french`` is true, the reading word is to be read starting
+    from the top row in French notation (= the bottom row in English notation).
+    If ``french`` is false, the reading word is to be read starting with the
+    top row in English notation.  
+
     EXAMPLES::
     
         sage: from sage.combinat.tableau import from_shape_and_word
@@ -1690 +1704 @@
         word: 4213
         sage: from_shape_and_word(shape, word)
         [[1, 3], [2], [4]]
+        sage: word = Word(flatten(t))
+        sage: from_shape_and_word(shape, word, False)
+        [[1, 3], [2], [4]]
+
     """
     res = []
     j = 0
-    for i in reversed(range(len(shape))):
-        res.append( list(w[j:j+shape[i]]) )
-        j += shape[i]
-    res.reverse()
+    if french:
+        for i in reversed(range(len(shape))):
+            res.append( list(w[j:j+shape[i]]) )
+            j += shape[i]
+        res.reverse()
+    else:
+        for i in range (len(shape)):
+            res.append(list(w[j:j+shape[i]]))
+            j += shape[i]
     return Tableau_class(res)
 
 def Tableaux(n=None):