Module aligner 

Two streams aligned note by note, as an edit from one to the other: music21’s alpha.analysis.aligner.

Structs

Change

A change from the target to the source: the target’s note, the source’s, and what became of it.

ChangePlace

Where a change stands: the places music21 reads the two hashes from, and what became of the note.

StreamAligner

Two streams aligned by their notes’ hashes, the cheapest edit from one to the other: music21’s StreamAligner.

Enums

ChangeOp

What becomes of a note from the target to the source: music21’s ChangeOps.

Functions

change_places

The cheapest edit from the target to the source read out of a matrix already filled, each change with the places of the two hashes it is between: the by-position twin of calculateChangesList.

default_hasher

A hasher for an alignment: music21’s StreamAligner.getDefaultHasher, which hashes no offset and says what each hash was made from.

delete_cost

What it costs to take a note out that the target has not got: music21’s deleteCost, which is the same count.

fill_distance_matrix

The cheapest edit onto every opening of the two, written into a matrix already set up: music21’s populateDistanceMatrix.

hashes_equal_without_reference

Whether two hashes say the same of a note, whatever each was made from: music21’s tupleEqualityWithoutReference.

insert_cost

What it costs to put a note in that the source has not got: music21’s insertCost, which is how many values the hash says.

moves_from_location

The costs of the three moves onto a cell – up, left and diagonally – each nothing where that cell is off the matrix: music21’s getPossibleMovesFromLocation.

num_similarities

How many of the values two hashes say alike: music21’s calculateNumSimilarities.

op_from_location

The change that leads to a cell: music21’s getOpFromLocation – none where the cost standing there is the cheapest move’s, otherwise the cheapest move, up before left before diagonal.

populate_distance_matrix

A matrix set up and filled in one: music21’s setupDistanceMatrix and populateDistanceMatrix together.

setup_distance_matrix

A matrix of the right size for an alignment, every cost nought: music21’s setupDistanceMatrix.

similarity_score

How much of an edit changes nothing: music21’s similarityScore.

substitution_cost

What it costs to turn one note’s hash into another’s: music21’s substitutionCost – nothing where the two say the same, otherwise how many of the values differ.