Minetest-WorldEditAdditions/worldeditadditions/utils/numbers.lua

-- From http://lua-users.org/wiki/SimpleRound
function worldeditadditions.round(num, numDecimalPlaces)
	local mult = 10^(numDecimalPlaces or 0)
	return math.floor(num * mult + 0.5) / mult
end

function worldeditadditions.hypotenuse(x1, y1, x2, y2)
	local xSquare = math.pow(x1 - x2, 2);
	local ySquare = math.pow(y1 - y2, 2);
	return math.sqrt(xSquare + ySquare);
end

function worldeditadditions.sum(list)
		if #list == 0 then return 0 end
	local sum = 0
	for i,value in ipairs(list) do
		sum = sum + value
	end
		return sum
end


function worldeditadditions.average(list)
	if #list == 0 then return 0 end
	return worldeditadditions.sum(list) / #list
end

--- Returns the minetest.get_us_time() in ms
-- @return	float
function worldeditadditions.get_ms_time()
	return minetest.get_us_time() / 1000
end

function worldeditadditions.eta(existing_times, done_count, total_count)
		local max = 100
		local average = worldeditadditions.average(
				worldeditadditions.table_get_last(existing_times, max)
		)
		local times_left = total_count - done_count
		if times_left == 0 then return 0 end
		return average * times_left
end

--- Returns the sign (+ or -) at the beginning of a string if present.
-- @param	src	string|int	Input string.
-- @return	string|int	Returns the signed multiplier (1|-1).
function worldeditadditions.getsign(src)
	if type(src) == "number" then return src < 0 and -1 or 1
	elseif type(src) ~= "string" then return 1
	else return src:match('-') and -1 or 1 end
end

-- For Testing:
-- worldeditadditions = {}
-- print(worldeditadditions.getsign('-y'))