local fmt = require "fmt"

local function sma(period)
    local i = 0
    local sum = 0
    local storage = {}
    return function(input)
        if #storage < period then
            sum += input
            storage:insert(input)
        end
        sum += input - storage[i + 1]
        storage[i + 1] = input
        i = (i + 1) % period
        return sum / #storage
    end
end

local sma3 = sma(3)
local sma5 = sma(5)
print("  x     sma3   sma5")
for {1, 2, 3, 4, 5, 5, 4, 3, 2, 1} as x do
    fmt.print("%5.3f  %5.3f  %5.3f", x, sma3(x), sma5(x))
end