nécessité le package : cluster</span></div><div class='output co'>#&gt;       US60                US90              US210             US390        
#&gt;  Min.   :-2.768413   Min.   :-2.36952   Min.   :-2.2557   Min.   :-2.6048  
#&gt;  1st Qu.:-0.231289   1st Qu.:-0.22754   1st Qu.:-0.0852   1st Qu.:-0.2729  
#&gt;  Median : 0.009688   Median :-0.02436   Median : 0.8850   Median : 0.3155  
#&gt;  Mean   :-0.104018   Mean   : 0.11805   Mean   : 0.7542   Mean   : 0.1994  
#&gt;  3rd Qu.: 0.155536   3rd Qu.