Module:Sandbox
This page is not an actual Scribunto module. It exists to provide editors a place to create experimental modules.
Naming your modules
To keep things tidy, please use the following format to name your experimental modules:
Module:Sandbox/Your username/Module name
Cleaning up unused modules
Experimental modules may be deleted by admins upon request or after a long period of inactivity.
List of modules in this area
For a list of the experimental modules under Module:Sandbox, see Special:PrefixIndex/Module:Sandbox/.
The above documentation is transcluded from Module:Sandbox/doc. 
Editors can experiment in this module's sandbox and testcases pages.
Subpages of this module.
Editors can experiment in this module's sandbox and testcases pages.
Subpages of this module.
local p = {}
local getArgs
function p.main(frame)
	if not getArgs then
		getArgs = require('Module:Arguments').getArgs
	end
	local args = getArgs(frame)
	return p._main(args[1], args[2])
end
function p._main(n, d)
	local num = tonumber(n)
	if not num then
		error('Unable to convert "' .. tostring(n) .. '" to a number')
	end
	local decimals = tonumber(d)
	if not decimals then
		error('Unable to convert "' .. tostring(d) .. '" to a number')
	end
	local maxDecimals = 14 - math.floor(math.log10(num)) -- to allow a maximum of 15 significant figures, which is the highest guaranteed correct with doubles
	if decimals > maxDecimals then decimals = maxDecimals end
	local mult = 10^decimals
	num = math.floor(num * mult + 0.5) / mult
	if decimals < 0 then
		return tostring(num)
	else
		return string.format('%.' .. decimals .. 'f', num)
	end
end
return p
