Data commit

Task/Permutation-test/Sidef/permutation-test.sidef

@@ -0,0 +1,20 @@
+func statistic(ab, a) {
+    var(sumab, suma) = (ab.sum, a.sum)
+    suma/a.size - ((sumab-suma) / (ab.size-a.size))
+}
+
+func permutationTest(a, b) {
+    var ab = (a + b)
+    var tobs = statistic(ab, a)
+    var under = (var count = 0)
+    ab.combinations(a.len, {|*perm|
+        statistic(ab, perm) <= tobs && (under += 1)
+        count += 1
+    })
+    under * 100 / count
+}
+
+var treatmentGroup = [85, 88, 75, 66, 25, 29, 83, 39, 97]
+var controlGroup   = [68, 41, 10, 49, 16, 65, 32, 92, 28, 98]
+var under = permutationTest(treatmentGroup, controlGroup)
+say ("under=%.2f%%, over=%.2f%%" % (under, 100 - under))