Data commit

Task/Averages-Simple-moving-average/E/averages-simple-moving-average-1.e

@@ -0,0 +1,22 @@
+pragma.enable("accumulator")
+def makeMovingAverage(period) {
+    def values := ([null] * period).diverge()
+    var index := 0
+    var count := 0
+
+    def insert(v) {
+        values[index] := v
+        index := (index + 1) %% period
+        count += 1
+    }
+
+    /** Returns the simple moving average of the inputs so far, or null if there
+        have been no inputs. */
+    def average() {
+        if (count > 0) {
+            return accum 0 for x :notNull in values { _ + x } / count.min(period)
+        }
+    }
+
+    return [insert, average]
+}

Task/Averages-Simple-moving-average/E/averages-simple-moving-average-2.e

@@ -0,0 +1,33 @@
+? for period in [3, 5] {
+>     def [insert, average] := makeMovingAverage(period)
+>     println(`Period $period:`)
+>     for value in [1,2,3,4,5,5,4,3,2,1] {
+>         insert(value)
+>         println(value, "\t", average())
+>     }
+>     println()
+> }
+
+Period 3:
+1	1.0
+2	1.5
+3	2.0
+4	3.0
+5	4.0
+5	4.666666666666667
+4	4.666666666666667
+3	4.0
+2	3.0
+1	2.0
+
+Period 5:
+1	1.0
+2	1.5
+3	2.0
+4	2.5
+5	3.0
+5	3.8
+4	4.2
+3	4.2
+2	3.8
+1	3.0