pyircor 0.2.0

Installation

You may install the stable release from PyPI using pip

pip install pyircor

Usage

tau and tauap implement the Kendall tau and Yilmaz tauAP correlation coefficients, where no ties are allowed between items:

from pyircor.tau import tau
from pyircor.tauap import tauap
import nupmy as np

x = np.array([0.06, 0.2, 0.27, 0.37, 0.57, 0.63, 0.66, 0.9, 0.91, 0.94])
y = np.array([0.37, 0.06, 0.2, 0.27, 0.57, 0.66, 0.63, 0.91, 0.9, 0.94])
tau(x, y)
# 0.7777777777777778
tauap(x, y)
# 0.7491181657848325

In tauap it is important to use the correct sorting order. By default, items are sorted in decreasing order, as should be for instance if the scores represent system effectiveness. When they should be in increasing order, decreasing should be set to False:

from pyircor.tauap import tauap

# these two calls are equivalent
tauap(x, y)
# 0.7491181657848325
tauap(-x, -y, decreasing=False)
# 0.7491181657848325

tau_a and tauap_a are versions to use when x represents a true ranking without ties, and y represents a ranking estimated by an observer who is allowed to produce ties. They can be used as a measure of accuracy of the observer with respect to the true ranking

from pyircor.tau import tau_a
from pyircor.tauap_a import tauap_a

y = np.round(y * 5) / 5
tau_a(x, y)
# 0.7111111111111111
tauap_a(x, y)
# 0.6074514991181656

tau_b and tauap_b are versions to use under the assumption that both x and y represent rankings estimated by two observers who may produce ties. They can be used as a measure of agreement between the observers:

x = np.round(x * 5) / 5
tau_b(x, y)
# 0.75
tauap_b(x, y)
# 0.626984126984127

Credits

Along with the codebase itself, many parts of this package, including docstrings and comments, are directly adopted under the original authors’ agreement. Please refer to the original work if you want to use this package for any publication.

This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.

Reference

@inproceedings{urbano2017ties,
  author = {Urbano, Juli{\'{a}}n and Marrero, M{\'{o}}nica},
  booktitle = {ACM SIGIR International Conference on the Theory of Information Retrieval},
  pages = {321--324},
  title = {{The Treatment of Ties in AP Correlation}},
  year = {2017}
}