Convert Temperatures

function ConvertTemp(num, toScale)
	assert(tonumber(num), 'ConvertTemp expects a number.')
	assert((toScale == 'c') or (toScale == 'f'),
		'ConvertTemp expects c or f as the scale to convert to.')

	local outTemp = 0

	if toScale == 'c' then
		outTemp = Round((5 / 9) * (num - 32))
	else
		outTemp = Round((9 / 5) * num + 32)
	end

	return outTemp
end

function Round(num, idp)
	assert(tonumber(num), 'Round expects a number.')
	local mult = 10 ^ (idp or 0)
	if num >= 0 then
		return math.floor(num * mult + 0.5) / mult
	else
		return math.ceil(num * mult - 0.5) / mult
	end
end