This is the module sandbox page for Module:Factorization (diff). See also the companion subpage for test cases (run). |
This module is rated as beta, and is ready for widespread use. It is still new and should be used with some caution to ensure the results are as expected. |
This module displays the factorization of a given number. Numbers smaller than 2 or greater than 1,000,000,000 return "Error: <number> out of range". Fractional numbers are rounded down.
- Parameters
- The first unnamed parameter is the number
product
- the symbol to be used to indicate times. Defaults to ·bold
- set to any value to make it boldserif
- set to any value to make it serifbig
- set to any value to make it bigprime
- set to any value to have prime numbers return an unformatted link to prime instead of the number
local p = {}
function p.factor(frame)
-- Consider calling the parser function #expr
-- to simplify a potential mathematical expression?
number = tonumber(frame.args[1])
if number == nil then
return '<strong class="error">Error: input not recognized as a number</strong>'
end
productSymbol = frame.args['product'] or '·'
bold = frame.args['bold'] and true
big = frame.args['big'] and true
serif = frame.args['serif'] and true
primeLink = frame.args['prime'] and true
number = math.floor(number)
if number < 2 or number > 1000000000 or number == math.huge then
return '<strong class="error">Error: ' .. number .. ' out of range</strong>'
end
result = ""
currentNumber = number
power = 0
divisor = 2
-- Attempt factoring by the value of the divisor
-- divisor increments by 2, except first iteration (2 to 3)
while divisor <= math.sqrt(currentNumber) do
power = 0
while currentNumber % divisor == 0 do
currentNumber = currentNumber / divisor
power = power + 1
end
-- Concat result and increment divisor
-- when divisor is 2, go to 3. All other times, add 2
result = result .. powerformat(divisor, power, productSymbol)
divisor = divisor + (divisor == 2 and 1 or 2)
end
if currentNumber ~= 1 then
result = result .. currentNumber .. ' ' .. productSymbol .. ' '
end
if currentNumber == number and primeLink then
return '[[prime number|prime]]'
end
result = string.sub(result,1,-4)
return format(result)
end
function powerformat(divisor, power, productSymbol)
if power < 1 then return ''
elseif power == 1 then return divisor .. ' ' .. productSymbol .. ' '
else return divisor .. '<sup>' .. power .. '</sup> ' .. productSymbol .. ' '
end
end
function format(numString)
if bold then
numString = '<b>'..numString..'</b>'
end
ret = (serif or big) and '<span ' or ''
if serif then ret = ret .. 'class="texhtml" ' end
if big then ret = ret .. 'style="font-size:165%" ' end
ret = ret .. ((serif or big) and '>' or '') .. numString .. ((serif or big) and '</span>' or '')
return ret
end
return p