Data commit

Task/Statistics-Basic/Ruby/statistics-basic.rb

@@ -0,0 +1,20 @@
+def generate_statistics(n)
+  sum = sum2 = 0.0
+  hist = Array.new(10, 0)
+  n.times do
+    r = rand
+    sum += r
+    sum2 += r**2
+    hist[(10*r).to_i] += 1
+  end
+  mean = sum / n
+  stddev = Math::sqrt((sum2 / n) - mean**2)
+
+  puts "size: #{n}"
+  puts "mean:   #{mean}"
+  puts "stddev: #{stddev}"
+  hist.each_with_index {|x,i| puts "%.1f:%s" % [0.1*i, "=" * (70*x/hist.max)]}
+  puts
+end
+
+[100, 1000, 10000].each {|n| generate_statistics n}