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Module:Math/doc

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Revision as of 01:39, 18 December 2013 by Mr. Stradivarius (talk | changes) (add precision function)

This is the documentation page for Module:Math


This module provides a number of mathematical functions. These functions can be used from #invoke or from other Lua modules.

Use from other Lua modules

To use the module from normal wiki pages, no special preparation is needed. If you are using the module from another Lua module, first you need to load it, like this:

local mm = require('Module:Math')

(The mm variable stands for Module Math; you can choose something more descriptive if you prefer.)

Most functions in the module have a version for Lua and a version for #invoke. It is possible to use the #invoke functions from other Lua modules, but using the Lua functions has the advantage that you do not need to access a Lua frame object. Lua functions are preceded by _, whereas #invoke functions are not.

random

{{#invoke:math|random}}
{{#invoke:math|random|max_value}}
{{#invoke:math|random|min_value|max_value}}
mm._random()
mm._random(max_value)
mm._random(min_value, max_value)

Generates a random number.

  • If no arguments are specified, the number produced is greater than or equal to 0 and less than 1.
  • If one argument is provided, the number produced is an integer between 1 and that argument. The argument must be a positive integer.
  • If two arguments are provided, the number produced is an integer between the first and second arguments. Both arguments must be integers, but can be negative.

This function will not work properly for numbers less than -2^32 and greater than 2^32 - 1 (although this may vary by hardware). If you need to use numbers outside of this range, it is recommended that you use Module:Random.

order

{{#invoke:math|order|n}}
mm._order(n)

Determines the order of magnitude of a number.

precision

{{#invoke:math|precision|n}}
{{#invoke:math|precision|x=n}}
mm._precision(number_string)

Detemines the precision of a number. For example, for "4" it will return "0", for "4.567" it will return "3", and for "100" it will return "-2".

The function attempts to parse the string representation of the number, and detects whether the number uses E notation. For this reason, when called from Lua, very large numbers or very precise numbers should be directly input as strings to get accurate results. If they are input as numbers, the Lua interpreter will change them to E notation and this function will return the precision of the E notation rather than that of the original number. This is not a problem when the number is called from #invoke, as all input from #invoke is in string format.