Averages/Median: Difference between revisions

<lang elena>#defineimport system'routines.

#defineimport system'math.

#defineimport extensions.

#class(extension) op

#method median

#var aSorted := self ascendant.

#var aLen := aSorted length.

if (aLen == 0)

? [ ^ nil. ];

! [

#var aMiddleIndex := aLen / 2.

if (aLen mod:2 == 0)

? [ ^ (aSorted@(aMiddleIndex - 1) + aSorted@aMiddleIndex) / 2. ];

! [ ^ aSorted@aMiddleIndex. ].

#symbol program =

#var a1 := (4.1r, 5.6r, 7.2r, 1.7r, 9.3r, 4.4r, 3.2r).

#var a2 := (4.1r, 7.2r, 1.7r, 9.3r, 4.4r, 3.2r).