math: Revert clone on median algorithm, perhaps need to revisit this. Call clump for moving-median

basis/math/statistics/statistics.factor

@@ -151,7 +151,6 @@ PRIVATE>
     bi kth-smallests first2 ;
 
 : median ( seq -- x )
-    clone
     dup length odd? [ lower-median ] [ medians + 2 / ] if ;
 
 ! quantile can be any n-tile. quartile is n = 4, percentile is n = 100

extra/math/extras/extras.factor

@@ -99,7 +99,7 @@ PRIVATE>
     [ 1 ] 2dip [ [ dupd swap - ] dip * + dup ] curry map nip ;
 
 : moving-median ( u n -- v )
-    <clumps> [ median ] map ;
+    clump [ median ] map ;
 
 : moving-supremum ( u n -- v )
     <clumps> [ supremum ] map ;