Module:Harmonic entropy

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This module primarily serves as a library for other modules and has no corresponding template.

This module provides a means to calculate harmonic Shannon entropy of a particular interval.

Introspection summary for Module:Harmonic entropy
Functions provided (2) Line Function Params Description 7 to_cents (invokable) (frame) 12 _to_cents (ratio, prec)	Lua modules required (3) Variable Module Functions used getArgs Module:Arguments getArgs rat Module:Rational dependency not used u Module:Utils eval_num_arg _log _round

---

local getArgs = require('Module:Arguments').getArgs
local u = require('Module:Utils')
local rat = require('Module:Rational')
local p = {}

-- return measure in cents of an interval ratio, rounded to prec decimal places
function p.to_cents(frame)
	local args = getArgs(frame)
	return p._to_cents(args[1], args[2])
end	

function p._to_cents(ratio, prec)
	-- ratio defaults to 1
	ratio = u.eval_num_arg(ratio, 1)
	-- prec defaults to nil
	prec = u.eval_num_arg(prec)
	local result = 1200*u._log(ratio), prec
	if prec == nil then
		return result
	else
		return u._round(result, prec)
	end
end

return p