Module:Pop density explained

---- This module implements --local p = local math_module = require("Module:Math")local precision = math_module._precisionlocal sortkey = require("Module:Sortkey")

local function rnd(num, digits) -- This function implements return math_module._precision_format(tostring(num), tostring(digits))endlocal unitnames = local unitmult = local unitstr =

local function popdensity(pop, area1, areaunit1, areaunit2, prec, disp, flip) local dens1, dens1sort, prec1 local dens2, dens2sort, prec2 local str1, str2 = , local uniterror = '^{?Unknown unit?}' if(pop ~= and area1 ~= ) then -- pop and area are defined local popnum = tonumber(pop) if not popnum then error(string.format('Unable to convert population "%s" to a number', pop), 2) end local area1num = tonumber(area1) if not area1num then error(string.format('Unable to convert area "%s" to a number', area1), 2) end local dens1num = popnum/area1num local unit1 = unitnames[areaunit1] or nil local unit2 = unitnames[areaunit2] or nil prec1 = (prec ~= ) and tonumber(prec) or (1+math.log10(2*area1/(1/10^precision(pop)+pop/area1/10^precision(area1)))) dens1 = rnd(dens1num, math.floor(prec1 + 0.5)) dens1sort = '

' if (unit1) then str1 = '/' .. unitstr[unit1] if(unit2) then -- convert local mult = unitmult[unit2]/unitmult[unit1] prec2 = prec1 - math.log10(mult) dens2 = rnd(dens1num*mult, math.floor(prec2 + 0.5)) dens2sort = '' str2 = '/' .. unitstr[unit2] elseif(areaunit2 ~= ) then if(disp ~= 'num') then dens2 = '?' else dens2 = '?' .. uniterror end str2 = '/' .. areaunit2 .. uniterror end elseif(areaunit1 ~= ) then if(disp ~= 'num') then dens2 = '?' else dens2 = '?' .. uniterror end if(unit2) then str2 = '/' .. unitstr[unit2] elseif(areaunit2 ~= ) then str2 = '/' .. areaunit2 .. uniterror end str1 = '/' .. areaunit1 .. uniterror end

-- form output if(str2 ~= ) then -- has a converted unit if(disp ~= 'num' and disp ~= 'table') then -- display input and output density numbers with units if(flip

'on') then return (dens2sort or ) .. dens2 .. str2 .. ' (' .. dens1 .. str1 .. ')' else return (dens1sort or ) .. dens1 .. str1 .. ' (' .. dens2 .. str2 .. ')' end elseif(disp

'table') then dens1 = (dens1sort or ) .. dens1 dens2 = (dens2sort or ) .. dens2 return pop .. '||' .. area1 .. '||' .. dens1 .. '||' .. dens2 else -- display output density number without unit return dens2 end else -- no converted unit if(disp ~= 'num' and disp ~= 'table') then -- display input density number with unit return (dens1sort or ) .. dens1 .. str1 elseif(disp

'table') then return pop .. '||' .. area1 .. '||' ..(dens1sort or ) .. dens1 else -- display input density number without unit return dens1 end end end return end

function p.density(frame) local args = (frame.args[3] ~= nil) and frame.args or frame:getParent.args return popdensity(args[1] or , args[2] or , args[3] or , args[4] or , args['prec'] or , args['disp'] or , args['flip'] or )end

return p