Data commit

Task/Statistics-Basic/Lua/statistics-basic.lua

@@ -0,0 +1,56 @@
+math.randomseed(os.time())
+
+function randList (n)  -- Build table of size n
+	local numbers = {}
+	for i = 1, n do
+		table.insert(numbers, math.random()) -- range correct by default
+	end
+	return numbers
+end
+
+function mean (t)  -- Find mean average of values in table t
+	local sum = 0
+	for k, v in pairs(t) do
+		sum = sum + v
+	end
+	return sum / #t
+end
+
+function stdDev (t)  -- Find population standard deviation of table t
+	local squares, avg = 0, mean(t)
+	for k, v in pairs(t) do
+		squares = squares + ((avg - v) ^ 2)
+	end
+	local variance = squares / #t
+	return math.sqrt(variance)
+end
+
+function showHistogram (t)  -- Draw histogram of given table to stdout
+	local histBars, compVal = {}
+	for range = 0, 9 do
+		histBars[range] = 0
+		for k, v in pairs(t) do
+			compVal = tonumber(string.format("%0.1f", v - 0.05))
+			if compVal == range / 10 then
+				histBars[range] = histBars[range] + 1
+			end
+		end
+	end
+	for k, v in pairs(histBars) do
+		io.write("0." .. k .. " " .. string.rep('=', v / #t * 200))
+		print(" " .. v)
+	end
+	print()
+end
+
+function showStats (tabSize)  -- Create and display statistics info
+	local numList = randList(tabSize)
+	print("Table of size " .. #numList)
+	print("Mean average: " .. mean(numList))
+	print("Standard dev: " .. stdDev(numList))
+	showHistogram(numList)
+end
+
+for power = 2, 5 do  -- Start of main procedure
+	showStats(10 ^ power)
+end