widget for frame jitter

function widget:GetInfo()
  return {
    name      = "Frame jitter",
    desc      = "logs frame jitter to file",
    author    = "Beherith - mysterme@gmail.com",
    date      = "2013 may",
    license   = "GNU GPL, v2 or later",
    layer     = 1000000, --last widget loaded
    enabled   = true  --  loaded by default?
  }
end

local timerold =0
--local file = io.open("example.txt", "w")
local oldframe = 0


function widget:GameFrame(n)
	if n>oldframe then
		oldframe=n
	else
		return
	end
	if timerold==0 then
		timerold=Spring.GetTimer()
	end
	local timernew=Spring.GetTimer()
	Spring.Echo('gameframe',n,'delta time',Spring.DiffTimers(timernew,timerold))
	timerold=timernew
end