September 2017 Update

Task/Averages-Arithmetic-mean/Nim/averages-arithmetic-mean.nim

@@ -1,6 +1,6 @@
 import strutils
 
-proc mean(xs): float =
+proc mean(xs: openArray[float]): float =
   for x in xs:
     result += x
   result = result / float(xs.len)
@@ -8,4 +8,4 @@ proc mean(xs): float =
 var v = @[1.0, 2.0, 2.718, 3.0, 3.142]
 for i in 0..5:
   echo "mean of first ", v.len, " = ", formatFloat(mean(v), precision = 0)
-  v.setLen(v.high)
+  if v.len > 0: v.setLen(v.high)