Module:Harmonic entropy: Difference between revisions

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Deprecating ET parsing and backslash ratio: those were ET-specific and not interval-specific. Functionality moved into Module:ET
Line 21: Line 21:
return u._round(result, prec)
return u._round(result, prec)
end
end
end
-- edf = ed3/2, edo = ed2, edt = ed3
local equaves =
{
  ['f'] = rat.new(3, 2),
  ['o'] = 2,
  ['t'] = 3
}
-- returns size of an ET given its name
function p.parse_ET_size(frame)
local args = getArgs(frame)
local size, equave = p.parse_ET(args[1])
return size
end
-- returns equave of an ET given its name
function p.parse_ET_equave(frame)
local args = getArgs(frame)
local size, equave = p.parse_ET(args[1])
return rat.as_float(equave)
end
-- returns size and equave of an ET given its name; cannot be used with {{#invoke:}}
function p.parse_ET(input)
input = string.lower(input)
local size, equave
-- size defaults to 12
size = u.eval_num_arg(input:match("^([0-9]+)"), 12)
if input:match("^[0-9]*[%-]?ed[fot]$") then
equave = equaves[tostring(input:match("[fot]"))]
else
-- equave defaults to 2
equave = rat.parse(input:match("^.-ed(.+)%s*$")) or 2
end
return size, equave
end
-- return ratio corresponding to an interval written in backslash notation
-- ("steps" of "size" equal divisions of the "equave")
function p.backslash_ratio(frame)
local args = getArgs(frame)
return p._backslash_ratio(args[1])
end
function p._backslash_ratio(input)
-- result defaults to 0
local result = 0
-- steps defaults to 1
local steps = input:match("%s*(%-?[0-9]+)\\.-") or 1
local size, equave = p.parse_ET(input:match("\\(.*)"))
if tonumber(size) == 0 then
return 1
end
result = rat.as_float(equave)^(tonumber(steps)/tonumber(size))
return result
end
end


return p
return p

Revision as of 19:21, 3 October 2022

Module documentation[view] [edit] [history] [purge]
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
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