diff --git a/pymath/stat/dataset.py b/pymath/stat/dataset.py
index 8ca0fff..81db07c 100644
--- a/pymath/stat/dataset.py
+++ b/pymath/stat/dataset.py
@@ -7,9 +7,9 @@
 #
 #
 
-from math import sqrt, cos, ceil
+from math import sqrt, ceil
 
-class Dataset():
+class Dataset(list):
     """ Classe réprésentant un série statistique avec rendu latex """
     
     def __init__(self, data = [], data_name = "Valeurs"):
@@ -19,9 +19,9 @@ class Dataset():
         :param data: values of the data set
         :param data_name: name of the data set
         """
-        self.data = list(data)
+        list.__init__(self, data)
 
-        self.data_name = data_name
+        self_name = data_name
 
     def add_data(self, data):
         """Add datas to the data set
@@ -29,19 +29,16 @@ class Dataset():
         :param data: datas
         """
         try:
-            self.data += data
+            self += data
         except TypeError:
-            self.data += [data]
+            self += [data]
 
     def sort(self, *args, **kwrds):
         """ Apply sort to data """
-        self.data.sort(*args, **kwrds)
-
-    def __len__(self):
-        return len(self.data)
+        self.sort(*args, **kwrds)
 
     def sum(self):
-        return sum(self.data)
+        return sum(self)
     
     def mean(self):
         return self.sum()/len(self) 
@@ -49,10 +46,10 @@ class Dataset():
     def deviation(self):
         """ Compute the deviation (not normalized) """
         mean = self.mean()
-        return sum([(x - mean)**2 for x in self.data])
+        return sum([(x - mean)**2 for x in self])
 
     def variance(self):
-        return self.deviation()/len(self.data)
+        return self.deviation()/len(self)
     
     def sd(self):
         """ Compute the standard deviation """
@@ -64,7 +61,7 @@ class Dataset():
 
         :return: (min, Q1, Me, Q3, Max)
         """
-        return (min(self.data) , self.quartile(1) , self.quartile(2) , self.quartile(3), max(self.data))
+        return (min(self) , self.quartile(1) , self.quartile(2) , self.quartile(3), max(self))
 
     def quartile(self, quartile = 1):
         """
@@ -82,7 +79,7 @@ class Dataset():
         """
         position = self.posi_quartile(quartile)[0]
         # À vérifier...
-        return self.data[position]
+        return self[position]
 
 
     def posi_quartile(self, quartile = 1):
@@ -215,7 +212,7 @@ On a ainsi $Q_{q} = {val_q}$
         """
         d_per_line = len(self) // nbr_lines
         d_last_line = len(self) % d_per_line
-        splited_data = [self.data[x:x+d_per_line] for x in range(0, len(self.data), d_per_line)]
+        splited_data = [self[x:x+d_per_line] for x in range(0, len(self), d_per_line)]
         # On ajoute les éléments manquant pour la dernière line
         if d_last_line:
             splited_data[-1] += [' ']*(d_per_line - d_last_line)