trees

exception decitala.trees.TreeException

Bases: Exception

exception decitala.trees.FragmentTreeException

Bases: decitala.trees.TreeException

class decitala.trees.FragmentTree(data, rep_type, name=None, **kwargs)

Bases: treeplotter.tree.Tree

NaryTree that holds multiplicative or additive representations of a rhythmic dataset.

Parameters

• data – either a path to folder of music21-readable files or a list of decitala.fragment.GeneralFragment objects (or its subclasses).

• rep_type (str) – determines the representation of the fragment. Options are "ratio", "difference", and "dseg".

• name (str) – optional name of the Fragment Tree.

Raises

FragmentTreeException – if an invalid path or rep_type is given.

>>> ratio_tree = FragmentTree.from_frag_type(frag_type="greek_foot", rep_type="ratio")
>>> ratio_tree
<trees.FragmentTree greek_foot_ratio: nodes=43>
>>> ratio_tree.search_for_path([1.0, 2.0, 0.5, 1.0]).name
<fragment.GreekFoot Peon_II>
>>> # We can also give it a name.
>>> from decitala.fragment import Decitala, GreekFoot, GeneralFragment
>>> g1 = GeneralFragment([1.0, 1.0, 1.0, 1.0, 1.0], name="myfragment")
>>> g2 = Decitala("Ragavardhana")
>>> g3 = GreekFoot("Ionic_Major")
>>> data = [g1, g2, g3]
>>> mytree = FragmentTree(data = data, rep_type="difference", name="MyCoolTree")
>>> mytree
<trees.FragmentTree MyCoolTree: nodes=10>
>>> for frag in sorted(mytree.all_named_paths(), key=lambda x: x.name):
...     print(frag)
<fragment.Decitala 93_Ragavardhana>
<fragment.GreekFoot Ionic_Major>
<fragment.GeneralFragment myfragment: [1. 1. 1. 1. 1.]>

classmethod from_frag_type(frag_type, rep_type)

Create a fragment tree from the data in fragment_database.db in the databases directory.

Parameters

frag_type (str) – determines the class defining the set of fragments. If the frag_type=='decitala', creates Decitala objects; if frag_type=='greek_foot', creates GreekFoot. Otherwise creates GeneralFragment (default) objects.

classmethod from_composition(filepath, part_num=0, rep_type='ratio', windows=[2, 3, 4, 5, 6, 7, 8, 9])

Class method for generating a FragmentTree from a composition.

Parameters

• filepath (str) – path to file.

• part_num (int) – part number.

Returns

a FragmentTree made from a rolling window of a part in a composition.

Return type

FragmentTree

classmethod from_multiple_paths(paths, rep_type, name=None)

Create a FragmentTree from a list of paths (each a directory of music21-readable files).

Parameters

paths (list) – list of paths (each a string), each a directory of music21-readable files of rhythmic fragments.

Returns

a Fragment tree holding multiple paths of data.

Return type

FragmentTree

show(save_path=None, verbose=False)

The vis module uses the Treant.js library to create a tree diagram. The diagram is stored in an HTML file, but is saved as a PDF using the R webshot package. This function does not save the directory, but returns a wand.Image object (with optionally saving it).