Module:Math: Difference between revisions
add a gcd function per edit request by User:Mxn, add a mod function, alter existing functions to allow access from Lua without calling a frame object, use Module:Arguments to process arguments, p._cleanNumber improvements
m>Dragons flight (add average) |
m>Mr. Stradivarius (add a gcd function per edit request by User:Mxn, add a mod function, alter existing functions to allow access from Lua without calling a frame object, use Module:Arguments to process arguments, p._cleanNumber improvements) |
||
Line 4: | Line 4: | ||
]] | ]] | ||
local yesno = require('Module:Yesno') | |||
local getArgs = require('Module:Arguments').getArgs | |||
local p = {} -- Holds functions to be returned from #invoke, and functions to make available to other Lua modules. | |||
local wrap = {} -- Holds wrapper functions that process arguments from #invoke. These act as intemediary between functions meant for #invoke and functions meant for Lua. | |||
--[[ | |||
Helper functions used to avoid redundant code. | |||
]] | |||
local function err(msg) | |||
-- Generates wikitext error messages. | |||
return mw.ustring.format('<strong class="error">Formatting error: %s</strong>', msg) | |||
end | |||
local function unpackNumberArgs(args) | |||
-- Returns an unpacked list of arguments specified with numerical keys. | |||
local ret = {} | |||
for k, v in pairs(args) do | |||
if type(k) == 'number' then | |||
table.insert(ret, v) | |||
end | |||
end | |||
return unpack(ret) | |||
end | |||
local function makeArgArray(...) | |||
-- Makes an array of arguments from a list of arguments that might include nils. | |||
local args = {...} -- Table of arguments. It might contain nils or non-number values, so we can't use ipairs. | |||
local nums = {} -- Stores the numbers of valid numerical arguments. | |||
local ret = {} | |||
for k, v in pairs(args) do | |||
v = p._cleanNumber(v) | |||
if v then | |||
nums[#nums + 1] = k | |||
args[k] = v | |||
end | |||
end | |||
table.sort(nums) | |||
for i, num in ipairs(nums) do | |||
ret[#ret + 1] = args[num] | |||
end | |||
return ret | |||
end | |||
local function applyFuncToArgs(func, ...) | |||
-- Use a function on all supplied arguments, and return the result. The function must accept two numbers as parameters, | |||
-- and must return a number as an output. This number is then supplied as input to the next function call. | |||
local vals = makeArgArray(...) | |||
local count = #vals -- The number of valid arguments | |||
if count == 0 then return | |||
-- Exit if we have no valid args, otherwise removing the first arg would cause an error. | |||
nil, 0 | |||
end | |||
local ret = table.remove(vals, 1) | |||
for _, val in ipairs(vals) do | |||
ret = func(ret, val) | |||
end | |||
return ret, count | |||
end | |||
--[[ | |||
random | |||
Generate a random number | |||
Usage: | |||
{{#invoke: Math | random }} | |||
{{#invoke: Math | random | maximum value }} | |||
{{#invoke: Math | random | minimum value | maximum value }} | |||
]] | |||
function wrap.random(args) | |||
local first = p._cleanNumber(args[1]) | |||
local second = p._cleanNumber(args[2]) | |||
return p._random(first, second) | |||
end | |||
function p._random(first, second) | |||
math.randomseed(mw.site.stats.edits + mw.site.stats.pages + os.time() + math.floor(os.clock() * 1000000000)) | |||
-- math.random will throw an error if given an explicit nil parameter, so we need to use if statements to check the params. | |||
if first and second then | |||
if first <= second then -- math.random doesn't allow the first number to be greater than the second. | |||
return math.random(first, second) | |||
end | |||
elseif first then | |||
return math.random(first) | |||
else | |||
return math.random() | |||
end | |||
end | end | ||
Line 26: | Line 103: | ||
Usage: | Usage: | ||
{{#invoke: Math | order | value }} | |||
]] | ]] | ||
function | |||
function wrap.order(args) | |||
local input_string = (args[1] or args.x or '0'); | |||
local input_number = p._cleanNumber(input_string); | |||
if input_number == nil then | |||
return err('order of magnitude input appears non-numeric') | |||
else | |||
return p._order(input_number) | |||
end | |||
end | end | ||
function | |||
function p._order(x) | |||
if x == 0 then return 0 end | |||
return math.floor(math.log10(math.abs(x))) | |||
end | end | ||
Line 50: | Line 127: | ||
Usage: | Usage: | ||
{{ #invoke: Math | precision | value }} | |||
]] | ]] | ||
function | |||
function wrap.precision(args) | |||
local input_string = (args[1] or args.x or '0'); | |||
local trap_fraction = args.check_fraction; | |||
local input_number; | |||
if yesno(trap_fraction, true) then -- Returns true for all input except nil, false, "no", "n", "0" and a few others. See [[Module:Yesno]]. | |||
local pos = string.find(input_string, '/', 1, true); | |||
if pos ~= nil then | |||
if string.find(input_string, '/', pos + 1, true) == nil then | |||
local denominator = string.sub(input_string, pos+1, -1); | |||
local denom_value = tonumber(denominator); | |||
if denom_value ~= nil then | |||
return math.log10(denom_value); | |||
end | |||
end | |||
end | |||
end | |||
input_number, input_string = p._cleanNumber(input_string); | |||
if input_string == nil then | |||
return err('precision input appears non-numeric') | |||
else | |||
return p._precision(input_string) | |||
end | |||
end | end | ||
function p._precision(x) | |||
if type(x) == 'number' then | |||
x = tostring(x) | |||
end | |||
x = string.upper(x) | |||
local decimal = x:find('%.') | |||
local exponent_pos = x:find('E') | |||
local result = 0; | |||
if exponent_pos ~= nil then | |||
local exponent = string.sub(x, exponent_pos + 1) | |||
x = string.sub(x, 1, exponent_pos - 1) | |||
result = result - tonumber(exponent) | |||
end | |||
if decimal ~= nil then | |||
result = result + string.len(x) - decimal | |||
return result | |||
end | |||
local pos = string.len(x); | |||
while x:byte(pos) == string.byte('0') do | |||
pos = pos - 1 | |||
result = result - 1 | |||
if pos <= 0 then | |||
return 0 | |||
end | |||
end | |||
return result | |||
end | end | ||
Line 123: | Line 195: | ||
Usage: | Usage: | ||
{{#invoke:Math| max | value1 | value2 | ... }} | |||
Note, any values that do not evaluate to numbers are ignored. | |||
]] | ]] | ||
function | |||
function wrap.max(args) | |||
return p._max(unpackNumberArgs(args)) | |||
end | |||
function p._max(...) | |||
local function maxOfTwo(a, b) | |||
if a > b then | |||
return a | |||
else | |||
return b | |||
end | |||
end | |||
local max_value = applyFuncToArgs(maxOfTwo, ...) | |||
if max_value then | |||
return max_value | |||
end | |||
end | end | ||
Line 159: | Line 224: | ||
Usage: | Usage: | ||
{{#invoke:Math| min | value1 | value2 | ... }} | |||
OR | OR | ||
{{#invoke:Math| min }} | |||
When used with no arguments, it takes its input from the parent | When used with no arguments, it takes its input from the parent | ||
frame. Note, any values that do not evaluate to numbers are ignored. | frame. Note, any values that do not evaluate to numbers are ignored. | ||
]] | ]] | ||
function | |||
function wrap.min(args) | |||
return p._min(unpackNumberArgs(args)) | |||
end | |||
function p._min(...) | |||
local function minOfTwo(a, b) | |||
if a < b then | |||
return a | |||
else | |||
return b | |||
end | |||
end | |||
local min_value = applyFuncToArgs(minOfTwo, ...) | |||
if min_value then | |||
return min_value | |||
end | |||
end | end | ||
--[[ | --[[ | ||
average | average | ||
Finds the average | Finds the average | ||
Usage: | Usage: | ||
{{#invoke:Math| average | value1 | value2 | ... }} | |||
OR | OR | ||
{{#invoke:Math| average }} | |||
Note, any values that do not evaluate to numbers are ignored. | |||
]] | ]] | ||
function | |||
function wrap.average(args) | |||
return p._average(unpackNumberArgs(args)) | |||
end | |||
function p._average(...) | |||
local function getSum(a, b) | |||
return a + b | |||
end | |||
local sum, count = applyFuncToArgs(getSum, ...) | |||
if not sum then | |||
return 0 | |||
else | |||
return sum / count | |||
end | |||
end | end | ||
Line 230: | Line 285: | ||
Usage: | Usage: | ||
{{#invoke:Math | round | value | precision }} | |||
--]] | |||
function wrap.round(args) | |||
local value = p._cleanNumber(args[1] or args.value or 0) | |||
local precision = p._cleanNumber(args[2] or args.precision or 0) | |||
if value == nil or precision == nil then | |||
return err('round input appears non-numeric') | |||
else | |||
return p._round(value, precision) | |||
end | |||
end | |||
function p._round(value, precision) | |||
local rescale = math.pow(10, precision or 0); | |||
return math.floor(value * rescale + 0.5) / rescale; | |||
end | |||
--[[ | |||
mod | |||
Implements the modulo operator | |||
Usage: | |||
{{#invoke:Math | mod | x | y }} | |||
--]] | |||
function wrap.mod(args) | |||
local x = p._cleanNumber(args[1]) | |||
local y = p._cleanNumber(args[2]) | |||
if not x then | |||
return err('first argument to mod appears non-numeric') | |||
elseif not y then | |||
return err('second argument to mod appears non-numeric') | |||
else | |||
return p._mod(x, y) | |||
end | |||
end | |||
function p._mod(x, y) | |||
local ret = x % y | |||
if not (0 <= ret and ret < y) then | |||
ret = 0 | |||
end | |||
return ret | |||
end | |||
--[[ | |||
gcd | |||
Calculates the greatest common divisor of multiple numbers | |||
Usage: | |||
{{#invoke:Math | gcd | value 1 | value 2 | value 3 | ... }} | |||
--]] | --]] | ||
function | |||
function wrap.gcd(args) | |||
return p._gcd(unpackNumberArgs(args)) | |||
end | end | ||
function | |||
function p._gcd(...) | |||
local function findGcd(a, b) | |||
local r = b | |||
local oldr = a | |||
while r ~= 0 do | |||
local quotient = math.floor(oldr / r) | |||
oldr, r = r, oldr - quotient * r | |||
end | |||
if oldr < 0 then | |||
oldr = oldr * -1 | |||
end | |||
return oldr | |||
end | |||
local result, count = applyFuncToArgs(findGcd, ...) | |||
return result | |||
end | end | ||
Line 257: | Line 371: | ||
Usage: | Usage: | ||
{{#invoke: Math | precision_format | number | precision }} | |||
]] | ]] | ||
function wrap.precision_format(args) | |||
local value_string = args[1] or 0 | |||
local precision = args[2] or 0 | |||
return p._precision_format(value_string, precision) | |||
end | |||
function p._precision_format(value_string, precision) | |||
-- For access to Mediawiki built-in formatter. | |||
local lang = mw.getContentLanguage(); | |||
local value | |||
value, value_string = p._cleanNumber(value_string) | |||
precision = p._cleanNumber(precision) | |||
-- Check for non-numeric input | |||
if value == nil or precision == nil then | |||
return err('invalid input when rounding') | |||
end | |||
local current_precision = p._precision(value) | |||
local order = p._order(value) | |||
-- Due to round-off effects it is neccesary to limit the returned precision under | |||
-- some circumstances because the terminal digits will be inaccurately reported. | |||
if order + precision >= 14 then | |||
orig_precision = p._precision(value_string) | |||
if order + orig_precision >= 14 then | |||
precision = 13 - order; | |||
end | |||
end | |||
-- If rounding off, truncate extra digits | |||
if precision < current_precision then | |||
value = p._round(value, precision) | |||
current_precision = p._precision(value) | |||
end | |||
local formatted_num = lang:formatNum(math.abs(value)) | |||
local sign | |||
-- Use proper unary minus sign rather than ASCII default | |||
if value < 0 then | |||
sign = '−' | |||
else | |||
sign = '' | |||
end | |||
-- Handle cases requiring scientific notation | |||
if string.find(formatted_num, 'E', 1, true) ~= nil or math.abs(order) >= 9 then | |||
value = value * math.pow(10, -order) | |||
current_precision = current_precision + order | |||
precision = precision + order | |||
formatted_num = lang:formatNum(math.abs(value)) | |||
else | |||
order = 0; | |||
end | |||
formatted_num = sign .. formatted_num | |||
-- Pad with zeros, if needed | |||
if current_precision < precision then | |||
local padding | |||
if current_precision <= 0 then | |||
if precision > 0 then | |||
local zero_sep = lang:formatNum(1.1) | |||
formatted_num = formatted_num .. zero_sep:sub(2,2) | |||
padding = precision | |||
if padding > 20 then | |||
padding = 20 | |||
end | |||
formatted_num = formatted_num .. string.rep('0', padding) | |||
end | |||
else | |||
padding = precision - current_precision | |||
if padding > 20 then | |||
padding = 20 | |||
end | |||
formatted_num = formatted_num .. string.rep('0', padding) | |||
end | |||
end | |||
-- Add exponential notation, if necessary. | |||
if order ~= 0 then | |||
-- Use proper unary minus sign rather than ASCII default | |||
if order < 0 then | |||
order = '−' .. lang:formatNum(math.abs(order)) | |||
else | |||
order = lang:formatNum(order) | |||
end | |||
formatted_num = formatted_num .. '<span style="margin:0 .15em 0 .25em">×</span>10<sup>' .. order .. '</sup>' | |||
end | |||
return formatted_num | |||
end | end | ||
Line 357: | Line 477: | ||
]] | ]] | ||
function | function p._cleanNumber(number_string) | ||
if type(number_string) == 'number' then | |||
-- We were passed a number, so we don't need to do any processing. | |||
return number_string, tostring(number_string) | |||
elseif type(number_string) ~= 'string' or not number_string:find('%S') then | |||
-- We were passed a non-string or a blank string, so exit. | |||
return nil, nil; | |||
end | |||
-- Attempt basic conversion | |||
local number = tonumber(number_string) | |||
-- If failed, attempt to evaluate input as an expression | |||
if number == nil then | |||
local frame = mw.getCurrentFrame() | |||
local attempt = frame:preprocess('{{#expr: ' .. number_string .. '}}') | |||
attempt = tonumber(attempt) | |||
if attempt ~= nil then | |||
number = attempt | |||
number_string = tostring(number) | |||
else | |||
number = nil | |||
number_string = nil | |||
end | |||
else | |||
number_string = number_string:match("^%s*(.-)%s*$") -- String is valid but may contain padding, clean it. | |||
number_string = number_string:match("^%+(.*)$") or number_string -- Trim any leading + signs. | |||
if number_string:find('^%-?0[xX]') then | |||
-- Number is using 0xnnn notation to indicate base 16; use the number that Lua detected instead. | |||
number_string = tostring(number) | |||
end | |||
end | |||
return number, number_string | |||
end | |||
--[[ | |||
Wrapper function that does basic argument processing. This ensures that all functions from #invoke can use either the current | |||
frame or the parent frame, and it also trims whitespace for all arguments and removes blank arguments. | |||
]] | |||
local function makeWrapper(funcName) | |||
return function (frame) | |||
local args = getArgs(frame) -- Argument processing is left to Module:Arguments. Whitespace is trimmed and blank arguments are removed. | |||
return wrap[funcName](args) | |||
end | |||
end | |||
for funcName in pairs(wrap) do | |||
p[funcName] = makeWrapper(funcName) | |||
end | end | ||
return | return p |