Open notkaramel opened 8 months ago
I am including here a few afterthoughts I had:
d d f
will be equal to g g b
if we consider the sequence of intervals 0 +2
, but they have different "heights" (different pitches).
So I was thinking that something like: c d d f
vs. e g g b
, will have the contour +1 0 +2
vs. +2 0 +2
and, therefore, the difference only lies on the first note.
If we are going to switch now to a "note-height" approach, we will need to consider an extra edit operation (in addition to the usual substitution, addition, and deletion): transposition, which in this context might mean adding or subtracting a fixed interval to a sub-sequence of notes. So maybe we should start looking for melodic comparison (with Needleman-Wunsch or others) that include a transposition operation.Thank you @martha-thomae, that's very insightful!
I've been debugging the current Needleman-Wunsch algorithm for the past couple of days and see if it can construct and analyse chants via its height/position first.
"[...] if we keep working with sequences of melodic intervals, we need to consider the effect of the edit operation (substitution, addition, deletion of note) in the following interval."
But isn't it the goal of the algorithm is to highlight these edits while keeping the the remainder of the chant to stay the same?
"[...] If we are going to switch now to a "note-height" approach, we will need to consider an extra edit operation (in addition to the usual substitution, addition, and deletion): transposition, which in this context might mean adding or subtracting a fixed interval to a sub-sequence of notes."
I agree and am testing this approach. Will update soon!
Sidenote: I made some indexing mistake for the matrix, making the row to be the column and vice versa. This lead to the analysis to be swapped. It's only recently that I fixed this issue.
To-do (for cross-comparison):
@loc
I removed the following item from the to-do list:
- [ ] Implement and test a different algorithm (e.g., Smith-Waterman) for cross-comparison analysis
Adding extra requirements and ideas/concerns (discussed with @martha-thomae) about highlight mismatches and gaps for cross comparison:
Delaying implementation of this feature (again) to focus on search functionalities
location + show differences on both sides
The current implementation of the analysis tool using Needleman-Wunsch algorithm is highlighting the contour between two chants. These mismatches and gaps are made of two notes, and in order to highlight them, we must highlight both notes that create it. This is a bit unintuitive and might be confusing to visually analyse.
To-do (for cross-comparison):