Averages/Mean time of day: Difference between revisions

</pre>

=={{header|Lua}}==

<lang lua>

local times = {"23:00:17","23:40:20","00:12:45","00:17:19"}

-- returns time converted to a radian format

local function timeToAngle(str)

local h,m,s = str:match("(..):(..):(..)")

return (h + m / 60 + s / 3600)/12 * math.pi

end

-- computes the mean of the angles inside a list

local function meanAngle(angles)

local sumSin,sumCos = 0,0

for k,v in pairs(angles) do

sumSin = sumSin + math.sin(v)

sumCos = sumCos + math.cos(v)

end

return math.atan2(sumSin,sumCos)

end

-- converts and angle back to a time string

local function angleToTime(angle)

local abs = angle % (math.pi * 2)

local time = abs / math.pi * 12

local h = math.floor(time)

local m = math.floor(time * 60) % 60

local s = math.floor(time * 3600) % 60

return string.format("%02d:%02d:%02d", h, m, s)

end

-- convert times to angles

for k,v in pairs(times) do

times[k] = timeToAngle(v)

end

print(angleToTime(meanAngle(times)))

</lang>

{{out}}

<pre>

23:47:43