Random numbers: Difference between revisions

Content added Content deleted

Inline

@@ Line 1,952: / Line 1,952: @@
  * Let's test it
  */
-def calcAvgAndStddev[T](ts: Iterable[T])(implicit num: Fractional[T]): (T, Double) = {
+  def calcAvgAndStddev[T](ts: Iterable[T])(implicit num: Fractional[T]): (T, Double) = {
+    val mean: T =
-  def avg(ts: Iterable[T])(implicit num: Fractional[T]): T = {
-    num.div(ts.sum, num.fromInt(ts.size)) // Leaving with type of function T
+      num.div(ts.sum, num.fromInt(ts.size)) // Leaving with type of function T
-  }
+    // Root of mean diffs
-  def mean = avg(ts)
+    val stdDev = sqrt(ts.map { x =>
+      val diff = num.toDouble(num.minus(x, mean))
+      diff * diff
+    }.sum / ts.size)
-  def stdDev = // Root of mean diffs
+    (mean, stdDev)
+  }
-    math.sqrt(num.toDouble(
-      ts.foldLeft(num.zero)((b, a) =>
-        num.plus(b, num.times(num.minus(a, mean), num.minus(a, mean))))) / ts.size)
-  (mean, stdDev)
-}
 println(calcAvgAndStddev(distrubution.take(1000))) // e.g. (1.0061433267806525,0.5291834867560893)</lang>