amads.algorithms.slice.window

amads.algorithms.slice.window#

Sliding window algorithm.

The algorithm segments a musical score into fixed-size windows that can optionally overlap. Each window contains all notes that are sounding within its time boundaries.

Author#

Peter Harrison

class amads.algorithms.slice.window.Window(time, size, align, candidate_notes, skip=0)[source]#

A fixed-size window of a musical score.

Parameters:

  • time (float) – The reference time for this window

  • size (float) – The size of the window in time units

  • align (str) – How to align the window relative to the reference time: - “left”: window starts at reference time - “center”: reference time is at window center - “right”: window ends at reference time

  • candidate_notes (Iterable[Note]) – Notes to consider for inclusion in this window, sorted by onset time and pitch

  • skip (int, default=0) – Index to start searching from in candidate_notes. This is used to optimize performance when iterating through multiple windows - each window can tell the next window which notes it can safely skip because they end before the window starts.

amads.algorithms.slice.window.sliding_window(passage, size, step=1.0, align='right', onset=0.0, offset=None, times=None) → Iterator[Window][source]#

Slice a score into (possibly overlapping) windows of a given size.

Parameters:

  • passage (Score or Iterable[Note]) – The musical passage to be windowed

  • size (float) – The size (duration) of each window (time units)

  • step (float, default=1.0) – The step size to take between windows (time units). For example, if step is 0.1, then a given slice will start 0.1 time units after the previous slice started. Note that if step is smaller than size, successive windows will overlap

  • align (str, default="right") – Each generated window has a time property that points to a particular timepoint in the musical passage. The align parameter determines how the window is aligned to this timepoint: - “left”: the window starts at window.time - “center”: window.time corresponds to the midpoint of the window - “right”: the window finishes at window.time

  • onset (float, default=0.0) – The desired time of the first window

  • offset (float, optional) – If set, the windowing will stop once the offset time is reached. Following the behaviour of Python’s built-in range function, offset is not treated inclusively, i.e. the last window will not include offset

  • times (Iterable[float], optional) – Optional iterable of times to generate windows for. If provided, onset and offset are ignored

Returns:

Iterator over the windows

Return type:

Iterator[Window]

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