Module:Scale tree

---

local p = {}
local MOS = require('Module:MOS')
local ET = require('Module:ET')
local u = require('Module:Utils')


local step_ratios = {
	{1, 1},
	{6, 5},
	{5, 4},
	{9, 7},
	{4, 3},
	{11, 8},
	{7, 5},
	{10, 7},
	{3, 2},
	{11, 7},
	{8, 5},
	{13, 8},
	{5, 3},
	{12, 7},
	{7, 4},
	{9, 5},
	{2, 1},
	{9, 4},
	{7, 3},
	{12, 5},
	{5, 2},
	{8, 3},
	{3, 1},
	{7, 2},
	{4, 1},
	{5, 1},
	{1, 0}
}

local step_ratios = {{1, 1}, {1, 0}}


function p.scale_tree(frame)
	local mos = MOS.parse(frame.args['tuning'])
	local equave = mos.equave
	local L = mos.nL
	local s = mos.ns
	local collapsed_et = ET.new(L, equave)
	local abstract_bright_gen = MOS.bright_gen(mos)
	local collapsed_bright_steps = abstract_bright_gen['L']
	local equalized_et = ET.new(L + s, equave)
	local equalized_bright_steps = abstract_bright_gen['L'] + abstract_bright_gen['s']
	local result = ""

	result = '{|class="wikitable"\n'
	result = result .. "|-\n"
	result = result .. "!Generator (chroma-positive)\n"
	result = result .. "!Cents (chroma-positive)\n"
	result = result .. "!L\n"
	result = result .. "!s\n"
	result = result .. "!Comments\n"
	local i = 1
	while i <= #step_ratios do
		local step_ratio = step_ratios[i]
		local et = ET.new(step_ratio[1] * L + step_ratio[2] * s)
		local generator_steps =  step_ratio[1] * collapsed_bright_steps + step_ratio[2] * (equalized_bright_steps - collapsed_bright_steps)
		local comments = frame.args[("comments_" .. step_ratio[1] .. "_" .. step_ratio[2])] or ""
		result = result .. "|-\n"
		result = result .. "|" .. generator_steps .. '\\' .. ET.backslash_modifier(et) .. "\n"
		result = result .. "|" .. generator_steps .. "\n"
		result = result .. "|" .. u._round(equave^(generator_steps / et.size), 4) .. "\n"
		result = result .. "|" .. step_ratio[1] .. "\n"
		result = result .. "|" .. step_ratio[2] .. "\n"
		result = result .. "|" .. u._round(step_ratio[1] / step_ratio[2], 3) .. "\n"

		result = result .. "|" .. comments .. "\n"

		i = i + 1
	end
		
	result = result .. "|}"
	return result
end
return p