Module:JI ratio finder: Difference between revisions

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@@ Line 4: / Line 4: @@
 local p = {}
--- Main function
+-- Finds candidate ratios up to a cent value and up to an integer limit
+-- Ratios found this way will range from 0 cents to the given cent value
+-- These ratios should then be filtered as needed
+function p.find_candidate_ratios(cents, int_limit)
+	local cents = cents or 1200
+	local int_limit = int_limit or 99
+	local candidate_ratios = {}
+	for i = 1, int_limit do
+		local denominator = i
+		local numerator = i
+		local is_within_cents = true
+		repeat
+			local current_ratio = rat.new(numerator, denominator)
+			local is_simplified = utils._gcd(numerator, denominator) == 1
+			is_within_cents = rat.cents(current_ratio) <= cents
+			if is_simplified and is_within_cents then
+				table.insert(candidate_ratios, current_ratio)
+			end
+			numerator = numerator + 1
+		until not is_within_cents
+	end
+	return candidate_ratios
+end
+-- Filter ratios based on whether they're within a cent range
+function p.filter_ratios_by_range(ratios, min_cents, max_cents)
+	local ratios = ratios or { rat.new(5, 4), rat.new(81, 64), rat.new(9, 7) }
+	local min_cents = min_cents or 380
+	local max_cents = max_cents or 420
+	local filtered_ratios = {}
+	for i = 1, #ratios do
+		local ratio_in_cents = rat.cents(ratios[i])
+		if ratio_in_cents >= min_cents and ratio_in_cents <= max_cents then
+			table.insert(filtered_ratios, ratios[i])
+		end
+	end
+	return filtered_ratios
+end
+-- Filters ratios by prime limit
+-- Filters out ratios whose prime factorizations contains primes larger than
+-- the prime limit
+function p.filter_ratios_by_prime_limit(ratios, prime_limit)
+	local ratios = ratios or { rat.new(5, 4), rat.new(81, 64), rat.new(9, 7) }
+	local prime_limit = prime_limit or 5
+	local filtered_ratios = {}
+	for i = 1, #ratios do
+		if rat.max_prime(ratios[i]) <= prime_limit then
+			table.insert(filtered_ratios, ratios[i])
+		end
+	end
+	return filtered_ratios
+end
+-- Filters ratios by odd limit
+-- Filters out ratios where, ignoring powers of 2, either the numerator or
+-- denominator exceeds the odd limit
+function p.filter_ratios_by_odd_limit(ratios, odd_limit)
+	local ratios = ratios or { rat.new(5, 4), rat.new(81, 64), rat.new(9, 7) }
+	local odd_limit = odd_limit or 5
+	local filtered_ratios = {}
+	for i = 1, #ratios do
+		if rat.odd_limit(ratios[i]) <= odd_limit then
+			table.insert(filtered_ratios, ratios[i])
+		end
+	end
+	return filtered_ratios
+end
+-- Filters ratios by harmonic class
+-- Filters out ratios whose largest prime is larger than the given prime; only
+-- ratios whose largest prime is the given harmonic class are kept
+function p.filter_ratios_by_harmonic_class(ratios, harmonic_class)
+	local ratios = ratios or { rat.new(5, 4), rat.new(81, 64), rat.new(9, 7) }
+	local harmonic_class = harmonic_class or 5
+	local filtered_ratios = {}
+	for i = 1, #ratios do
+		if rat.max_prime(ratios[i]) == harmonic_class then
+			table.insert(filtered_ratios, ratios[i])
+		end
+	end
+	return filtered_ratios
+end
+-- Filters ratios by Tenney height
+-- Filters ratios where lg(numerator) + lg(denominator) does not exceed the
+-- given height, where lg is log-base-2
+function p.filter_ratios_by_tenney_height(ratios, tenney_height)
+	local ratios = ratios or { rat.new(5, 4), rat.new(81, 64), rat.new(9, 7) }
+	local tenney_height = tenney_height or 5.0
+	local filtered_ratios = {}
+	for i = 1, #ratios do
+		if rat.tenney_height(ratios[i]) <= tenney_height then
+			table.insert(filtered_ratios, ratios[i])
+		end
+	end
+	return filtered_ratios
+end
 -- Finds approximated JI ratios for a cent value for a prime and odd limit
+-- Meant to find ratios within the range of a single cent value
+-- TODO: use integer limit instead of odd limit
 function p.find_ratios_for_cents(cents, tolerance, prime_limit, odd_limit)
 	local cents = cents or 700
@@ Line 59: / Line 176: @@
 end
-function p.ratios_to_text(ratios)
+-- Converts ratios to text, with delimiter
+-- Default delimiter is a comma followed by a space
+function p.ratios_to_text(ratios, delimiter)
 	local ratios = ratios or { rat.new(5, 4), rat.new (81, 64) }
+	local delimiter = delimiter or ", "
 	local text = ""
@@ Line 66: / Line 186: @@
 		text = text .. rat.as_ratio(ratios[i])
 		if i ~= #ratios then
-			text = text .. ", "
+			text = text .. delimiter
 		end
 	end
 	return text
 end
 return p