Module:MOS: Difference between revisions

-- This module follows [[User:Ganaram inukshuk/Provisional style guide for Lua]]

local et    = require("Module:ET")

local rat   = require("Module:Rational")

 

----------------------------- MOS-CREATING FUNCTIONS ---------------------------

-- Create a new mos as a table containing the counts for large and small steps,

-- plus the equave.

-- Parse a mos from its scalesig "xL ys<p/q>" or "xL ys (p/q-equivalent)".

-- If no equave "p/q" is provided, it's assumed to be 2/1-equivalent.

local nL, ns, equave = unparsed:match("^(%d+)[Ll].-(%d+)[Ss]%s*(.*)$")

 

 

 

 

--------------------------------------------------------------------------------

---------------------------- STRING/LINK FUNCTIONS -----------------------------

-- Scalesig is "xL ys <p/q>" for valid mosses, omitting <p/q> for 2/1 scales.

-- Option to use nbsp is provided using the second param; default is nbsp.

function p.as_string(mos, use_nbsp)

if p.is_valid(mos) then

local suffix = ""

if not rat.eq(mos.equave, 2) then

suffix = "⟨" .. rat.as_ratio(mos.equave):lower() .. "⟩"

function p.as_long_string(mos, use_nbsp)

if p.is_valid(mos) then

local suffix = ""

if not rat.eq(mos.equave, 2) then

suffix = (use_nbsp and "&nbsp;" or " ") .. string.format("(%s-equivalent)", rat.as_ratio(mos.equave):lower())

return math.max(mos.nL, mos.ns) .. p.et_suffix(mos)

 

local link = p.as_long_string(mos)

local text = p.as_string(mos)

return string.format("[[%s]]", link)

return string.format("[[%s|%s]]", link, text)

 

-- Construct the link to a mos, where the displayed text is the long string

-- instead. Degenerate mosses link to the corresponding equal-division page.

function p.as_long_link(mos)

local link = p.as_long_string(mos)

return string.format("[[%s]]", link)

-- Find the darkest true-mos mode of a mos. It's the reverse of the brightest mode.

-- Ordering here is based on the number of BRIGHT GENS DOWN PER PERIOD:

function p.mode_by_brightness(mos, bright_gens_down)

-- List all unique rotations for a mode, by order of leftward shifts. Order by

-- but this is expected if the order isn't by brightness (EG, modmosses).

-- (where s mod p = 0), then there will be p modes. If the mode has one step

-- type, then there is only one mode.

if not utils.table_contains(rotations, current_mode) then

-- shift it to the right. Helper function for mode_by_brightness().

--------------- FUNCTIONS FOR GENERATOR AND PERIOD INTERVALS -------------------

-- Compute the bright gen as a vector of L's and s's. Since all mosstep

-- intervals (excluding the root and period) have two sizes, this returns the

-- large/perfect size.

-- Compute the dark gen as a vector of L's and s's. Since all mosstep

-- intervals (excluding the root and period) have two sizes, this returns the

-- small/perfect size.

-- Period intervals as mossteps only appear as one size.

-- Equaves as mossteps only appear as one size. For a single-period mos, this

-- is the same as p.period().

------------------- FUNCTIONS FOR SINGLE-STEP INTERVALS ------------------------

-- Return the unison as a vector of L's and s's.

-- Return the vector for a single chroma. It's a large step minus a small step.

-- Return the vector for an augmented step. It's a large step plus a chroma.

-- Return the vector for a single large step.

-- Return the vector for a single small step.

-- Return the vector for a diminished step. It's a small step minus a chroma.

-- Compute an arbitrary mos interval as a vector of L's and s's. Params:

-- - step_count: the number of steps subtended by the mosstep.

-- - size_offset: denotes whether to return the large size (0) or the small

--   size (-1) (or if this is a period interval, the diminished size). Values

--   other than 0 or 1 represent alterations by multiple chromas, such as

--   augmented (1) or diminished (-2).

-- - L: large step.

-- - s: small step.

-- - c: a chroma; the difference between a large and small step.

-- - A: an augmented step; a large step plus a chroma.

-- - d: a diminished step, or diesis; a small step minus a chroma.

-- TODO: deprecate this since "equave_step_count" is redundant and longer than

-- "step count".

-- size_offset denotes whether to count chromas from the large size; changing

-- this to -1 counts chromas from the small size. Like size_offset for

-- interval_from_mos, this can be used to denote altered mossteps (augmented,

-- diminished, etc).

--------------- INTERVAL ARITHMETIC AND MANIPULATION FUNCTIONS -----------------

-- Stack an interval, or repeatedly add the same interval to itself.

-- interval to add to produce the period. For single-period mosses, the period

-- complement is the same as the equave complement.

function p.as_et(mos, step_ratio, suffix)

-- Given a mos and a step ratio, return the number of et-steps for its dark generator.

-- Given an interval vector and step ratio, compute the number of et-steps it corresponds to.

-- Given an interval vector and step ratio, convert it to cents. This requires info about the mos itself.

 

return  

p.mode_by_brightness(p.new(5,2), 2) .. " " .. p.mode_by_brightness(p.new(5,2), 6-4) .. "\n" ..

p.mode_by_brightness(p.new(5,2), 3) .. " " .. p.mode_by_brightness(p.new(5,2), 6-3) .. "\n" ..

p.mode_by_brightness(p.new(5,2), 5) .. " " .. p.mode_by_brightness(p.new(5,2), 6-1) .. "\n" ..