Module:MOS genchain: Difference between revisions

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@@ Line 114: / Line 114: @@
 	--	.. result
+	return result
+end
+function p.mos_genchain_description(input_mos)
+	local input_mos = input_mos or mos.new(6,2)
+	-- How many periods?
+	local period_count = mos.period_count(input_mos)
+	local period_interval = mos.period(input_mos)
+	-- What are the period intervals?
+	local period_intervals = {}
+	for i = 1, period_count + 1 do
+		local interval = mos.interval_mul(period_interval, i-1)
+		table.insert(period_intervals, interval)
+	end
+	-- As a sentence piece
+	local period_intervals_as_text = ""
+	if #period_intervals == 2 then
+		period_intervals_as_text = string.format("%s and %s", tamnams.degree_quality(period_intervals[1], input_mos), tamnams.degree_quality(period_intervals[2], input_mos))
+	else
+		for i = 1, period_count do
+			period_intervals_as_text = period_intervals_as_text
+				.. string.format("%s, ", tamnams.degree_quality(period_intervals[i], input_mos))
+		end
+		period_intervals_as_text = period_intervals_as_text
+			.. string.format("and %s", tamnams.degree_quality(period_intervals[period_count + 1], input_mos))
+	end
+	-- What is the bright gen and at what scale degrees do you stack from?
+	local bright_gen_as_text = tamnams.interval_quality(mos.bright_gen(input_mos), input_mos)
+	local result = string.format("A chain of bright generators, each a %s, produces the following scale degrees.", bright_gen_as_text)
+	-- How long is the chain?
+	local period_step_count = mos.period_step_count(input_mos)
+	local scalesig = mos.as_string(input_mos)
+	result = result
+		.. " "
+		.. string.format("A chain of %s consecutive scale degrees %sproduces one of the modes of %s.", period_step_count, (period_count == 1 and "" or "for each period "), scalesig)
+	-- What scales are produced when the chain is extended further?
+	local child_scale_chain_length = input_mos.nL + input_mos.nL + input_mos.ns
+	local child_scale_1 = mos.new(input_mos.nL+input_mos.ns, input_mos.nL, input_mos.equave)
+	local child_scale_2 = mos.new(input_mos.nL, input_mos.nL+input_mos.ns, input_mos.equave)
+	result = result
+		.. " "
+		.. string.format("Expanding %s chain to %s scale degrees produces the modes of either %s or %s.",
+			(period_count == 1 and "the" or "each"),
+			child_scale_chain_length / period_count,
+			mos.as_string(child_scale_1),
+			mos.as_string(child_scale_2)
+		)
 	return result
 end
@@ Line 121: / Line 175: @@
 	local input_mos = mos.parse(scalesig) or mos.new(5,2)
-	return p._mos_genchain(input_mos)
+	return p.mos_genchain_description(input_mos) .. "\n" .. p._mos_genchain(input_mos)
 end
 return p