Mô đun:Math/sandbox

--

This module provides a number of basic mathematical operations.

local yesno, getArgs -- lazily initialized

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('Lỗi định dạng: %s', 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 fold(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

--
Fold arguments by selectively choosing values (func should return when to choose the current "dominant" value).

local function binary_fold(func, ...)
local value = fold((function(a, b) if func(a, b) then return a else return b end end), ...)
return value
end

--
random

Generate a random number

Usage:

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 b end), ...)
if max_value then
return max_value
end
end

--
median

Find the median of set of numbers

Usage:

OR

function wrap.median(args)
return p._median(unpackNumberArgs(args))
end

function p._median(...)
local vals = makeArgArray(...)
local count = vals
table.sort(vals)

if count 0 then
return 0
end

if p._mod(count, 2) 0 then
return (vals[count/2] + vals[count/2+1])/2
else
return vals[math.ceil(count/2)]
end
end

--
min

Finds the minimum argument

Usage:

OR

When used with no arguments, it takes its input from the parent
frame. Note, any values that do not evaluate to numbers are ignored.

function wrap.min(args)
return p._min(unpackNumberArgs(args))
end

function p._min(...)
local min_value = binary_fold((function(a, b) return a = 14 then
if order + p._precision(value_string) >= 14 then
precision = 13 - order;
end
end

-- If rounding off, truncate extra digits
if precision = 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 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 ×10' .. order ..
end

return formatted_num
end

--
divide

Implements the division operator

Usage:

--
function wrap.divide(args)
local x = args[1]
local y = args[2]
local round = args.round
local precision = args.precision
if not yesno then
yesno = require('Module:Yesno')
end
return p._divide(x, y, yesno(round), precision)
end

function p._divide(x, y, round, precision)
if y nil or y "" then
return err("Không có số chia")
elseif not tonumber(y) then
if type(y) 'string' and string.sub(y, 1, 1) '<' then
return y
else
return err("Không phải là số: " .. y)
end
elseif x nil or x "" then
return err("Không có số bị chia")
elseif not tonumber(x) then
if type(x) 'string' and string.sub(x, 1, 1) '<' then
return x
else
return err("Không phải là số: " .. x)
end
else
local z = x / y
if round then
return p._round(z, 0)
elseif precision then
return p._round(z, precision)
else
return z
end
end
end

--
Helper function that interprets the input numerically. If the
input does not appear to be a number, attempts evaluating it as
a parser functions expression.

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 success, result = pcall(mw.ext.ParserFunctions.expr, number_string)
if success then
number = tonumber(result)
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 mt = { __index = function(t, k)
return function(frame)
if not getArgs then
getArgs = require('Module:Arguments').getArgs
end
return wrap[k](getArgs(frame)) -- Argument processing is left to Module:Arguments. Whitespace is trimmed and blank arguments are removed.
end
end }

return setmetatable(p, mt)