chandas

Code to recognize various Sanskrit meters.

All of the hard work was done by the sanskrit-programmers group, especially the first implementation by shreevatsa. I've rewritten the code with a more streamlined API, and eventually I may merge it into the sanskrit package.

The code supports any of the following metrical forms:

• sama-vṛtta
• ardha-sama-vṛtta
• viṣama-vṛtta
• jāti, including āryā

Quickstart

from chandas import Classifier
classifier = Classifier.from_json_file('data/data.json')

data = """
    kaScit kAntAvirahaguruRA svADikArapramattaH
    SApenAstaMgamitamahimA varzaBogyeRa BartuH .
    yakzaScakre janakatanayAsnAnapuRyodakezu
    snigDacCAyAtaruzu vasatiM rAmagiryASramezu .. 1 ..
    """

result = classifier.classify(data)
assert result and result.name == u'mandākrāntā'

The classifier works in SLP1, so you must transliterate all data to that format before passing it to the classifier.

Testing (requires pytest)

py.test test/*.py

To profile the code on some sample verses, run:

python -m cProfile -s cumulative profile.py

Modules

• wrappers.py for working with input data
• padyas.py for representing metrical forms
• classify.py for matching some input data with a metrical form
• enums.py for storing certain kinds of common data

JSON format

A list of objects, each with these keys:

• name: the name of the meter. By default, all names are in lowercase IAST, but any representation is allowed.

• pattern: a list of syllable patterns. A pattern is just a string that uses the following characters.

  • 'G' for guru syllables
  • 'L' for laghu syllables
  • '.' for syllables that can be either guru or laghu
  • '|' for yati. (Currently, the package just ignores this.)

  All other characters in the pattern (including whitespace) are ignored.

  If the list has 1 pattern, then the verse is treated as sama-vṛtta. If the list has 2 patterns, then the verse is treated as ardha-sama-vṛtta. If the list has 4 patterns, then the verse is treated as viṣama-vṛtta.

• counts: [optional] for jāti meters. A list of 4 numbers, each denoting the mātrā length of the corresponding pāda.

  If this field is present, then the verse is treated as a jāti meter.

Examples:

{
  "name": "mandākrāntā",
  "pattern": ["GGGG|LLLLLG|GLGGLGG"]
},
{
  "name": "upacitra",
  "pattern":["LLGLLGLLGLG", "GLLGLLGLLGG"]
},
{
  "name": "udgatā",
  "pattern": [
    "L L G L G L L L G L",
    "L L L L L G L G L G",
    "G L L L L L L G L L G",
    "L L G L G L L L G L G L G"
  ]
},
{
  "name": "āryā",
  "pattern": [],
  "counts": [12, 18, 12, 15]
}