Module:Decimals

require('Module:No globals')

local p = {}

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

function p.main(frame) local args, pargs = frame.args, frame:getParent().args return p._main(mw.ext.ParserFunctions.expr(args[1] or pargs[1]), mw.ext.ParserFunctions.expr(args[2] or pargs[2])) end

return p