Helper class with static utility functions for music analysis, pitch/duration conversion, and MusicXML processing. More...

#include <helper.h>

Static Public Member Functions
static std::vector< std::string >	splitString (const std::string &s, char delimiter)
	Splits a string into tokens using a specified delimiter. More...

static std::string	formatFloat (float floatValue, int digits)
	Formats a floating-point number as a string with a given number of decimal digits. More...

static const std::string	generateIdentation (int identPosition, int identSize=2)
	Generates a string of spaces for indentation, useful for pretty-printing MusicXML. More...

static std::pair< std::string, int >	ticks2noteType (int durationTicks, int divisionsPerQuarterNote, int actualNotes=1, int normalNotes=1)
	Converts a duration in ticks to a MusicXML note type and dot count. More...

static std::pair< RhythmFigure, int >	ticks2rhythmFigure (int durationTicks, int divisionsPerQuarterNote, int actualNotes, int normalNotes)
	Converts a duration in ticks to a RhythmFigure and dot count. More...

static int	noteType2ticks (std::string noteType, const int divisionsPerQuarterNote=256)
	Converts a MusicXML note type string to a duration in ticks. More...

static float	pitch2number (const std::string &pitch)
	Converts a pitch string (e.g., "C4") to a floating-point number representation. More...

static const std::string	number2pitch (const float number, const std::string &accType=MUSIC_XML::ACCIDENT::SHARP)
	Converts a floating-point pitch number to a pitch string, with optional accidental type. More...

static std::pair< int, int >	freq2midiNote (const float freq, std::function< int(float)> modelo=nullptr)
	Converts a frequency in Hz to the closest MIDI note and cents deviation. More...

static float	midiNote2freq (const int midiNote, const float freqA4=440.0f)
	Converts a MIDI note number to frequency in Hz. More...

static int	midiNote2octave (const int midiNote)
	Converts a MIDI note number to its octave number. More...

static int	pitch2midiNote (const std::string &pitch)
	Converts a pitch string (e.g., "C4") to a MIDI note number. More...

static const std::string	midiNote2pitch (const int midiNote, const std::string &accType={})
	Converts a MIDI note number to a pitch string, with optional accidental type. More...

static const std::vector< std::string >	midiNote2pitches (const int midiNote)
	Returns all possible pitch spellings for a given MIDI note. More...

static std::vector< Interval >	notes2Intervals (const std::vector< Note > &notes, const bool firstNoteAsReference=false)
	Computes intervals between a sequence of notes. More...

static std::vector< Interval >	notes2Intervals (const std::vector< std::string > &pitches, const bool firstNoteAsReference=false)
	Computes intervals between a sequence of pitch strings. More...

static int	semitonesBetweenPitches (const std::string &pitch_A, const std::string &pitch_B)
	Calculates the number of semitones between two pitch strings. More...

static float	noteSimilarity (std::string &pitchClass_A, int octave_A, const float duration_A, std::string &pitchClass_B, int octave_B, const float duration_B, float &durRatio, float &pitRatio, const bool enableEnharmonic=false)
	Computes multidimensional similarity between two notes using pitch-space and rhythmic metrics. More...

static float	pitch2freq (const std::string &pitch)
	Converts a pitch string to its frequency in Hz. More...

static int	frequencies2cents (const float freq_A, const float freq_B)
	Converts a frequency ratio between two pitches to cents. More...

static float	freq2equalTemperament (const float freq, const float referenceFreq=440.0f)
	Converts a frequency to the nearest equal-tempered frequency. More...

static std::string	rhythmFigure2noteType (const RhythmFigure rhythmFigure)
	Converts a RhythmFigure enum to a MusicXML note type string. More...

static int	rhythmFigure2Ticks (const RhythmFigure rhythmFigure, const int divisionsPerQuarterNote=256)
	Converts a RhythmFigure to a duration in ticks. More...

static RhythmFigure	noteType2RhythmFigure (const std::string &noteType)
	Converts a MusicXML note type string to a RhythmFigure enum. More...

static const std::string	transposePitch (const std::string &pitch, const int semitones, const std::string &accType=MUSIC_XML::ACCIDENT::SHARP)
	Transposes a pitch string by a number of semitones. More...

static bool	isEnharmonic (const std::string &pitch_A, const std::string &pitch_B)
	Checks if two pitch strings are enharmonically equivalent. More...

static void	splitPitch (const std::string &pitch, std::string &pitchClass, std::string &pitchStep, int &octave, float &alterValue, std::string &alterSymbol)
	Splits a pitch string into its components: pitch class, step, octave, accidental value, and symbol. More...

static float	durationRatio (float duration_A, float duration_B)
	Computes the ratio between two durations. More...

static const std::string	alterName2symbol (const std::string &alterName)
	Converts an accidental name (e.g., "sharp") to its symbol (e.g., "#"). More...

static float	alterSymbol2Value (const std::string &alterSymbol)
	Converts an accidental symbol (e.g., "#") to its numeric value. More...

static const std::string	alterValue2symbol (const float alterValue)
	Converts an accidental value to its symbol (e.g., 1.0 -> "#"). More...

static const std::string	alterValue2Name (const float alterValue)
	Converts an accidental value to its name (e.g., 1.0 -> "sharp"). More...

static void	getNoteNodeData (const pugi::xml_node &node, std::string &pitch, std::string &pitchClass, std::string &alterSymbol, int &alterValue, int &octave, std::string &type, float &duration)
	Retrieves detailed information from a MusicXML note node. More...

static const pugi::xpath_node_set	getNodeSet (const pugi::xml_document &doc, const std::string &xPath)
	Selects nodes from a MusicXML document using an XPath expression. More...

static const nlohmann::json	getPercentiles (const nlohmann::json &table, const std::vector< float > &desiredPercentiles)
	Returns a JSON object with percentiles for a given table and desired percentile values. More...

static std::pair< std::string, int >	freq2pitch (const float freq, const std::string &accType=MUSIC_XML::ACCIDENT::NONE)
	Converts a frequency in Hz to the closest pitch and cents deviation. More...

static float	pitchRatio (const std::string &pitch_A, const std::string &pitch_B)
	Computes the ratio between two pitch strings as a float. More...

static std::string	toString (const RhythmFigure rhythmFigure)
	Converts a RhythmFigure to a string. More...

static std::vector< float >	getSemitonesDifferenceBetweenMelodies (const std::vector< Note > &referenceMelody, const std::vector< Note > &otherMelody)
	Computes the intervallic contour difference vector between two melodic sequences. More...

static float	calculateMelodyEuclideanSimilarity (const std::vector< Note > &melodyPattern, const std::vector< Note > &otherMelody)
	Calculates Euclidean distance-based melodic similarity from intervallic contour comparison. More...

static float	calculateMelodyEuclideanSimilarity (const std::vector< float > &semitonesDifference)
	Calculates the Euclidean similarity from a vector of semitone differences. More...

static std::vector< float >	getDurationDifferenceBetweenRhythms (const std::vector< Note > &referenceRhythm, const std::vector< Note > &otherRhythm)
	Computes the vector of normalized duration differences between two rhythms. More...

static float	calculateRhythmicEuclideanSimilarity (const std::vector< Note > &rhythmPattern, const std::vector< Note > &otherRhythm)
	Calculates the Euclidean similarity between two rhythms based on duration differences. More...

static float	calculateRhythmicEuclideanSimilarity (const std::vector< float > &durationDifferences)
	Calculates the Euclidean similarity from a vector of duration differences. More...

Detailed Description

Helper class with static utility functions for music analysis, pitch/duration conversion, and MusicXML processing.

This class provides a wide range of static methods for manipulating musical data, including pitch and rhythm conversions, MusicXML node handling, similarity calculations, and more. All methods are designed for use in music research and computational musicology.

Member Function Documentation

◆ alterName2symbol()

static const std::string Helper::alterName2symbol ( const std::string & alterName )

static

Converts an accidental name (e.g., "sharp") to its symbol (e.g., "#").

Parameters

alterName Accidental name.

Returns: Accidental symbol.

◆ alterSymbol2Value()

static float Helper::alterSymbol2Value ( const std::string & alterSymbol )

static

Converts an accidental symbol (e.g., "#") to its numeric value.

Parameters

alterSymbol Accidental symbol.

Returns: Numeric value (e.g., 1.0 for "#").

◆ alterValue2Name()

static const std::string Helper::alterValue2Name ( const float alterValue )

static

Converts an accidental value to its name (e.g., 1.0 -> "sharp").

Parameters

alterValue Accidental value.

Returns: Accidental name.

◆ alterValue2symbol()

static const std::string Helper::alterValue2symbol ( const float alterValue )

static

Converts an accidental value to its symbol (e.g., 1.0 -> "#").

Parameters

alterValue Accidental value.

Returns: Accidental symbol.

◆ calculateMelodyEuclideanSimilarity() [1/2]

static float Helper::calculateMelodyEuclideanSimilarity ( const std::vector< float > & semitonesDifference )

static

Calculates the Euclidean similarity from a vector of semitone differences.

Parameters

semitonesDifference Vector of semitone differences.

Returns: Similarity value in [0,1].

◆ calculateMelodyEuclideanSimilarity() [2/2]

static float Helper::calculateMelodyEuclideanSimilarity	(	const std::vector< Note > &	melodyPattern,
		const std::vector< Note > &	otherMelody
	)

static

Calculates Euclidean distance-based melodic similarity from intervallic contour comparison.

Parameters

melodyPattern	Reference melodic pattern to match against.
otherMelody	Candidate melody to compare for similarity.

Returns: Normalized similarity score in [0,1] where 1.0 = identical contour, 0.0 = maximal divergence.

Computes global melodic similarity by measuring the Euclidean distance in pitch-space between two melodic sequences, accounting for transposition, intervallic distortion, and contour preservation. This metric is transposition-sensitive, meaning exact transpositions yield high similarity while contour-preserving transformations with interval alterations yield moderate similarity.

Computation Process:

Extract semitone difference vector: getSemitonesDifferenceBetweenMelodies(melodyPattern, otherMelody)
Compute Euclidean distance: sqrt(Σ(difference[i]²))
Normalize to [0,1] similarity: similarity = 1 / (1 + distance/scaling_factor)

Interpretation of Results:

similarity ≈ 1.0 (0.95-1.0): Near-identical melodies, possibly exact transposition
similarity ≈ 0.7-0.9: High similarity with minor intervallic variations (e.g., chromatic alterations, octave displacements in 1-2 notes)
similarity ≈ 0.4-0.7: Moderate similarity, recognizable contour with significant transformations (e.g., modal transposition, rhythmic variation, ornamentation)
similarity < 0.4: Low similarity, different melodic material or inverted contours

Transposition Invariance: This metric is NOT fully transposition-invariant. Melodies transposed by a constant interval will have high but not perfect similarity (distance proportional to transposition distance). For exact transposition-invariance, compute interval sequence differences instead.

Applications:

Melodic pattern matching in thematic analysis (identifying motivic recurrence)
Theme-and-variation studies (quantifying melodic transformation degree)
Plagiarism detection (measuring melodic borrowing/paraphrase)
Music information retrieval (query-by-example melodic search)
Corpus analysis (clustering melodies by contour similarity)

Note: Both melodies must have the same length for meaningful comparison. If lengths differ, the function processes min(melodyPattern.size(), otherMelody.size()) notes.

Warning: This metric emphasizes pitch contour over rhythmic structure. For combined pitch+rhythm similarity, use findMelodyPattern() with custom similarity callbacks.

◆ calculateRhythmicEuclideanSimilarity() [1/2]

static float Helper::calculateRhythmicEuclideanSimilarity ( const std::vector< float > & durationDifferences )

static

Calculates the Euclidean similarity from a vector of duration differences.

Parameters

durationDifferences Vector of duration differences.

Returns: Similarity value in [0,1].

◆ calculateRhythmicEuclideanSimilarity() [2/2]

static float Helper::calculateRhythmicEuclideanSimilarity	(	const std::vector< Note > &	rhythmPattern,
		const std::vector< Note > &	otherRhythm
	)

static

Calculates the Euclidean similarity between two rhythms based on duration differences.

Parameters

rhythmPattern	Reference rhythm.
otherRhythm	Comparison rhythm.

Returns: Similarity value in [0,1].

◆ durationRatio()

static float Helper::durationRatio	(	float	duration_A,
		float	duration_B
	)

static

Computes the ratio between two durations.

Parameters

duration_A	Duration of note A.
duration_B	Duration of note B.

Returns: Ratio in [0,1], where 1 means identical durations.

◆ formatFloat()

static std::string Helper::formatFloat	(	float	floatValue,
		int	digits
	)

static

Formats a floating-point number as a string with a given number of decimal digits.

Parameters

floatValue	The value to format.
digits	Number of decimal digits.

Returns: Formatted string.

◆ freq2equalTemperament()

static float Helper::freq2equalTemperament	(	const float	freq,
		const float	referenceFreq = `440.0f`
	)

static

Converts a frequency to the nearest equal-tempered frequency.

Parameters

freq	Input frequency.
referenceFreq	Reference frequency (default: 440.0 Hz).

Returns: Nearest equal-tempered frequency.

◆ freq2midiNote()

static std::pair< int, int > Helper::freq2midiNote	(	const float	freq,
		std::function< int(float)>	modelo = `nullptr`
	)

static

Converts a frequency in Hz to the closest MIDI note and cents deviation.

Parameters

freq	Frequency in Hz.
modelo	Optional custom mapping function.

Returns: Pair of MIDI note number and cents deviation.

◆ freq2pitch()

static std::pair< std::string, int > Helper::freq2pitch	(	const float	freq,
		const std::string &	accType = `MUSIC_XML::ACCIDENT::NONE`
	)

static

Converts a frequency in Hz to the closest pitch and cents deviation.

Parameters

freq	Frequency in Hz.
accType	Accidental type for output pitch.

Returns: Pair of pitch string and cents deviation.

◆ frequencies2cents()

static int Helper::frequencies2cents	(	const float	freq_A,
		const float	freq_B
	)

static

Converts a frequency ratio between two pitches to cents.

Parameters

freq_A	Frequency of the first pitch.
freq_B	Frequency of the second pitch.

Returns: Interval in cents.

◆ generateIdentation()

static const std::string Helper::generateIdentation	(	int	identPosition,
		int	identSize = `2`
	)

static

Generates a string of spaces for indentation, useful for pretty-printing MusicXML.

Parameters

identPosition	Indentation level.
identSize	Number of spaces per level (default: 2).

Returns: String with the requested indentation.

◆ getDurationDifferenceBetweenRhythms()

static std::vector< float > Helper::getDurationDifferenceBetweenRhythms	(	const std::vector< Note > &	referenceRhythm,
		const std::vector< Note > &	otherRhythm
	)

static

Computes the vector of normalized duration differences between two rhythms.

Parameters

referenceRhythm	Vector of reference notes.
otherRhythm	Vector of comparison notes.

Returns: Vector of duration differences.

◆ getNodeSet()

static const pugi::xpath_node_set Helper::getNodeSet	(	const pugi::xml_document &	doc,
		const std::string &	xPath
	)

static

Selects nodes from a MusicXML document using an XPath expression.

Parameters

doc	XML document.
xPath	XPath query string.

Returns: Set of matching XML nodes.

◆ getNoteNodeData()

static void Helper::getNoteNodeData	(	const pugi::xml_node &	node,
		std::string &	pitch,
		std::string &	pitchClass,
		std::string &	alterSymbol,
		int &	alterValue,
		int &	octave,
		std::string &	type,
		float &	duration
	)

static

Retrieves detailed information from a MusicXML note node.

Parameters

node	XML node of the note.
pitch	Output: pitch string.
pitchClass	Output: pitch class.
alterSymbol	Output: accidental symbol.
alterValue	Output: accidental value.
octave	Output: octave.
type	Output: note type.
duration	Output: duration.

◆ getPercentiles()

static const nlohmann::json Helper::getPercentiles	(	const nlohmann::json &	table,
		const std::vector< float > &	desiredPercentiles
	)

static

Returns a JSON object with percentiles for a given table and desired percentile values.

Parameters

table	Input JSON table.
desiredPercentiles	Vector of percentiles (0.0 to 1.0).

Returns: JSON object with percentile values.

◆ getSemitonesDifferenceBetweenMelodies()

static std::vector< float > Helper::getSemitonesDifferenceBetweenMelodies	(	const std::vector< Note > &	referenceMelody,
		const std::vector< Note > &	otherMelody
	)

static

Computes the intervallic contour difference vector between two melodic sequences.

Parameters

referenceMelody	Vector of notes representing the reference melodic pattern.
otherMelody	Vector of notes to compare against the reference melody.

Returns: Vector of signed semitone differences (positive = upward transposition, negative = downward).

Calculates the interval-by-interval pitch displacement between two melodies of equal length, producing a difference vector that quantifies melodic transposition, contour divergence, and pitch-space transformation. This function is fundamental for melodic similarity analysis, thematic variation studies, and computational pattern matching.

Computation Process: For each aligned note pair (referenceMelody[i], otherMelody[i]):

Compute signed semitone distance: otherMelody[i].pitch - referenceMelody[i].pitch
Positive values indicate upward transposition (otherMelody higher than reference)
Negative values indicate downward transposition (otherMelody lower than reference)
Zero values indicate exact pitch match at that position

Example:

referenceMelody: C4-E4-G4 (semitone sequence: 60-64-67)
otherMelody:     D4-F#4-A4 (semitone sequence: 62-66-69)
Difference vector: [+2, +2, +2] → uniform transposition up by major second

Interpretation of Results:

Constant difference vector (e.g., [+5, +5, +5]): Exact transposition
Zero-centered fluctuations (e.g., [-1, 0, +1]): Approximate contour match with chromatic variation
Large absolute values (e.g., [+12, +7, -3]): Significant contour divergence, octave displacements
Alternating signs: Contour inversion or melodic inversion transformation

Applications:

Melodic variation analysis (identifying theme-and-variation relationships)
Fugue analysis (detecting transposed subject entries at different pitch levels)
Melodic similarity scoring (input to calculateMelodyEuclideanSimilarity)
Contour analysis (studying intervallic contour preservation vs. transformation)
Computational musicology (corpus-wide melodic relationship detection)

Note: Both melodies must have the same length. If lengths differ, the function processes min(referenceMelody.size(), otherMelody.size()) notes and ignores excess notes.

Warning: This function compares absolute pitch, not pitch-class. C4 and C5 differ by 12 semitones. For pitch-class comparison (octave-invariant), reduce results modulo 12.

◆ isEnharmonic()

static bool Helper::isEnharmonic	(	const std::string &	pitch_A,
		const std::string &	pitch_B
	)

static

Checks if two pitch strings are enharmonically equivalent.

Parameters

pitch_A	First pitch string.
pitch_B	Second pitch string.

Returns: True if pitches are enharmonic.

◆ midiNote2freq()

static float Helper::midiNote2freq	(	const int	midiNote,
		const float	freqA4 = `440.0f`
	)

static

Converts a MIDI note number to frequency in Hz.

Parameters

midiNote	MIDI note number.
freqA4	Reference frequency for A4 (default: 440.0 Hz).

Returns: Frequency in Hz.

◆ midiNote2octave()

static int Helper::midiNote2octave ( const int midiNote )

static

Converts a MIDI note number to its octave number.

Parameters

midiNote MIDI note number.

Returns: Octave number.

◆ midiNote2pitch()

static const std::string Helper::midiNote2pitch	(	const int	midiNote,
		const std::string &	accType = `{}`
	)

static

Converts a MIDI note number to a pitch string, with optional accidental type.

Parameters

midiNote	MIDI note number.
accType	Accidental type (e.g., "#", "b").

Returns: Pitch string.

◆ midiNote2pitches()

static const std::vector< std::string > Helper::midiNote2pitches ( const int midiNote )

static

Returns all possible pitch spellings for a given MIDI note.

Parameters

midiNote MIDI note number.

Returns: Vector of pitch strings.

◆ notes2Intervals() [1/2]

static std::vector< Interval > Helper::notes2Intervals	(	const std::vector< Note > &	notes,
		const bool	firstNoteAsReference = `false`
	)

static

Computes intervals between a sequence of notes.

Parameters

notes	Vector of Note objects.
firstNoteAsReference	If true, intervals are from the first note to each subsequent note.

Returns: Vector of Interval objects.

◆ notes2Intervals() [2/2]

static std::vector< Interval > Helper::notes2Intervals	(	const std::vector< std::string > &	pitches,
		const bool	firstNoteAsReference = `false`
	)

static

Computes intervals between a sequence of pitch strings.

Parameters

pitches	Vector of pitch strings.
firstNoteAsReference	If true, intervals are from the first note to each subsequent note.

Returns: Vector of Interval objects.

◆ noteSimilarity()

static float Helper::noteSimilarity	(	std::string &	pitchClass_A,
		int	octave_A,
		const float	duration_A,
		std::string &	pitchClass_B,
		int	octave_B,
		const float	duration_B,
		float &	durRatio,
		float &	pitRatio,
		const bool	enableEnharmonic = `false`
	)

static

Computes multidimensional similarity between two notes using pitch-space and rhythmic metrics.

Parameters

pitchClass_A	Pitch class of note A (e.g., "C", "F#", "Bb").
octave_A	Octave register of note A (MIDI octave numbering: A4=440Hz).
duration_A	Duration of note A in quarter-note units (1.0 = quarter, 0.5 = eighth).
pitchClass_B	Pitch class of note B.
octave_B	Octave register of note B.
duration_B	Duration of note B in quarter-note units.
durRatio	Output parameter: rhythmic similarity ratio in [0,1].
pitRatio	Output parameter: pitch proximity ratio in [0,1].
enableEnharmonic	If true, treats enharmonic equivalents as identical (C# ≡ Db).

Returns: Overall similarity score in [0,1] where 1.0 = perfect identity, 0.0 = maximal dissimilarity.

Calculates composite similarity by combining pitch-space distance and rhythmic congruence, enabling flexible note-matching for melodic pattern recognition, variation analysis, and approximate music information retrieval.

Similarity Components:

Pitch Similarity (pitRatio):
- Computed as inverse exponential decay function of semitone distance
- Adjacent semitones (C→C#) → high similarity (≈0.9)
- Octave displacement (C4→C5) → moderate similarity (≈0.6-0.7)
- Large intervals (C4→G5) → low similarity (≈0.2-0.4)
- When enableEnharmonic=true: C# and Db are treated as identical (distance=0)
Rhythmic Similarity (durRatio):
- Computed as inverse ratio of duration difference
- Identical durations → durRatio = 1.0
- Augmentation/diminution by factor of 2 (quarter vs. half) → durRatio ≈ 0.5
- Large durational differences (whole vs. sixteenth) → durRatio → 0.0
Combined Similarity (return value):
- Weighted combination: similarity = α × pitRatio + β × durRatio
- Default weighting emphasizes pitch over rhythm (typical: α=0.7, β=0.3)

Applications:

Melodic pattern matching with tolerance for ornamentation and metric variation
Variation analysis (comparing theme vs. variations in sonata/rondo forms)
Approximate music search (query-by-humming with pitch/rhythm flexibility)
Voice-leading analysis (tracking note continuity across harmonic changes)
Motivic analysis with rhythmic transformation (augmentation, diminution)

Note: This is a local (note-to-note) similarity metric. For global melodic similarity (entire phrase comparison), use calculateMelodyEuclideanSimilarity() instead.

◆ noteType2RhythmFigure()

static RhythmFigure Helper::noteType2RhythmFigure ( const std::string & noteType )

static

Converts a MusicXML note type string to a RhythmFigure enum.

Parameters

noteType Note type string (e.g., "quarter").

Returns: RhythmFigure value.

◆ noteType2ticks()

static int Helper::noteType2ticks	(	std::string	noteType,
		const int	divisionsPerQuarterNote = `256`
	)

static

Converts a MusicXML note type string to a duration in ticks.

Parameters

noteType	Note type string (e.g., "quarter").
divisionsPerQuarterNote	Divisions per quarter note (default: 256).

Returns: Duration in ticks.

◆ number2pitch()

static const std::string Helper::number2pitch	(	const float	number,
		const std::string &	accType = `MUSIC_XML::ACCIDENT::SHARP`
	)

static

Converts a floating-point pitch number to a pitch string, with optional accidental type.

Parameters

number	Numeric pitch representation.
accType	Accidental type (e.g., "#", "b").

Returns: Pitch string.

◆ pitch2freq()

static float Helper::pitch2freq ( const std::string & pitch )

static

Converts a pitch string to its frequency in Hz.

Parameters

pitch Pitch string (e.g., "A4").

Returns: Frequency in Hz.

◆ pitch2midiNote()

static int Helper::pitch2midiNote ( const std::string & pitch )

static

Converts a pitch string (e.g., "C4") to a MIDI note number.

Parameters

pitch Pitch string.

Returns: MIDI note number.

◆ pitch2number()

static float Helper::pitch2number ( const std::string & pitch )

static

Converts a pitch string (e.g., "C4") to a floating-point number representation.

Parameters

pitch Pitch string.

Returns: Numeric representation of the pitch.

◆ pitchRatio()

static float Helper::pitchRatio	(	const std::string &	pitch_A,
		const std::string &	pitch_B
	)

static

Computes the ratio between two pitch strings as a float.

Parameters

pitch_A	First pitch string.
pitch_B	Second pitch string.

Returns: Ratio in [0,1].

◆ rhythmFigure2noteType()

static std::string Helper::rhythmFigure2noteType ( const RhythmFigure rhythmFigure )

static

Converts a RhythmFigure enum to a MusicXML note type string.

Parameters

rhythmFigure RhythmFigure value.

Returns: Note type string (e.g., "quarter").

◆ rhythmFigure2Ticks()

static int Helper::rhythmFigure2Ticks	(	const RhythmFigure	rhythmFigure,
		const int	divisionsPerQuarterNote = `256`
	)

static

Converts a RhythmFigure to a duration in ticks.

Parameters

rhythmFigure	RhythmFigure value.
divisionsPerQuarterNote	Divisions per quarter note (default: 256).

Returns: Duration in ticks.

◆ semitonesBetweenPitches()

static int Helper::semitonesBetweenPitches	(	const std::string &	pitch_A,
		const std::string &	pitch_B
	)

static

Calculates the number of semitones between two pitch strings.

Parameters

pitch_A	First pitch string.
pitch_B	Second pitch string.

Returns: Number of semitones from pitch_A to pitch_B.

◆ splitPitch()

static void Helper::splitPitch	(	const std::string &	pitch,
		std::string &	pitchClass,
		std::string &	pitchStep,
		int &	octave,
		float &	alterValue,
		std::string &	alterSymbol
	)

static

Splits a pitch string into its components: pitch class, step, octave, accidental value, and symbol.

Parameters

pitch	Input pitch string.
pitchClass	Output: pitch class (e.g., "C#", "Bb").
pitchStep	Output: step (e.g., "C", "D").
octave	Output: octave number.
alterValue	Output: accidental value as float.
alterSymbol	Output: accidental symbol (e.g., "#", "b").

◆ splitString()

static std::vector< std::string > Helper::splitString	(	const std::string &	s,
		char	delimiter
	)

static

Splits a string into tokens using a specified delimiter.

Parameters

s	The input string.
delimiter	The character used to split the string.

Returns: Vector of substrings.

◆ ticks2noteType()

static std::pair< std::string, int > Helper::ticks2noteType	(	int	durationTicks,
		int	divisionsPerQuarterNote,
		int	actualNotes = `1`,
		int	normalNotes = `1`
	)

static

Converts a duration in ticks to a MusicXML note type and dot count.

Parameters

durationTicks	Duration in ticks.
divisionsPerQuarterNote	Divisions per quarter note.
actualNotes	Tuplet numerator (default: 1).
normalNotes	Tuplet denominator (default: 1).

Returns: Pair of note type string and number of dots.

◆ ticks2rhythmFigure()

static std::pair< RhythmFigure, int > Helper::ticks2rhythmFigure	(	int	durationTicks,
		int	divisionsPerQuarterNote,
		int	actualNotes,
		int	normalNotes
	)

static

Converts a duration in ticks to a RhythmFigure and dot count.

Parameters

durationTicks	Duration in ticks.
divisionsPerQuarterNote	Divisions per quarter note.
actualNotes	Tuplet numerator.
normalNotes	Tuplet denominator.

Returns: Pair of RhythmFigure and number of dots.

◆ toString()

static std::string Helper::toString ( const RhythmFigure rhythmFigure )

static

Converts a RhythmFigure to a string.

Parameters

rhythmFigure RhythmFigure value.

Returns: String representation.

◆ transposePitch()

static const std::string Helper::transposePitch	(	const std::string &	pitch,
		const int	semitones,
		const std::string &	accType = `MUSIC_XML::ACCIDENT::SHARP`
	)

static

Transposes a pitch string by a number of semitones.

Parameters

pitch	Input pitch string.
semitones	Number of semitones to transpose.
accType	Accidental type for output pitch (default: "#").

Returns: Transposed pitch string.

The documentation for this class was generated from the following file:

maiacore/include/maiacore/helper.h

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ alterName2symbol()

◆ alterSymbol2Value()

◆ alterValue2Name()

◆ alterValue2symbol()

◆ calculateMelodyEuclideanSimilarity() [1/2]

◆ calculateMelodyEuclideanSimilarity() [2/2]

◆ calculateRhythmicEuclideanSimilarity() [1/2]

◆ calculateRhythmicEuclideanSimilarity() [2/2]

◆ durationRatio()

◆ formatFloat()

◆ freq2equalTemperament()

◆ freq2midiNote()

◆ freq2pitch()

◆ frequencies2cents()

◆ generateIdentation()

◆ getDurationDifferenceBetweenRhythms()

◆ getNodeSet()

◆ getNoteNodeData()

◆ getPercentiles()

◆ getSemitonesDifferenceBetweenMelodies()

◆ isEnharmonic()

◆ midiNote2freq()

◆ midiNote2octave()

◆ midiNote2pitch()

◆ midiNote2pitches()

◆ notes2Intervals() [1/2]

◆ notes2Intervals() [2/2]

◆ noteSimilarity()

◆ noteType2RhythmFigure()

◆ noteType2ticks()

◆ number2pitch()

◆ pitch2freq()

◆ pitch2midiNote()

◆ pitch2number()

◆ pitchRatio()

◆ rhythmFigure2noteType()

◆ rhythmFigure2Ticks()

◆ semitonesBetweenPitches()

◆ splitPitch()

◆ splitString()

◆ ticks2noteType()

◆ ticks2rhythmFigure()

◆ toString()

◆ transposePitch()