from mgcpy.independence_tests.abstract_class import IndependenceTest
from scipy.stats import kendalltau, spearmanr
[docs]class KendallSpearman(IndependenceTest):
def __init__(self, compute_distance_matrix=None, which_test='kendall'):
"""
:param compute_distance_matrix: a function to compute the pairwise distance matrix, given a data matrix
:type compute_distance_matrix: FunctionType or callable()
:param which_test: specifies which test to use, including 'kendall' or 'spearman'
:type which_test: str
"""
IndependenceTest.__init__(self, compute_distance_matrix)
self.which_test = which_test
[docs] def test_statistic(self, matrix_X, matrix_Y):
"""
Computes the Spearman's rho or Kendall's tau measure between two datasets.
- Implments scipy.stats's implementation for both
:param matrix_X: a [n*1] data matrix, a matrix with n samples in 1 dimension
:type matrix_X: 1D numpy.array
:param matrix_Y: a [n*1] data matrix, a matrix with n samples in 1 dimension
:type matrix_Y: 1D numpy.array
:return: returns a list of two items, that contains:
- :test_stat_: test statistic
- :test_statistic_metadata_: (optional) a ``dict`` of metadata other than the p_value,
that the independence tests computes in the process
:rtype: float, dict
**Example:**
>>> import numpy as np
>>> from mgcpy.independence_tests.kendall_spearman import KendallSpearman
>>> X = np.array([0.07487683, -0.18073412, 0.37266440, 0.06074847, 0.76899045,
0.51862516, -0.13480764, -0.54368083, -0.73812644, 0.54910974]).reshape(-1, 1)
>>> Y = np.array([-1.31741173, -0.41634224, 2.24021815, 0.88317196, 2.00149312,
1.35857623, -0.06729464, 0.16168344, -0.61048226, 0.41711113]).reshape(-1, 1)
>>> kendall_spearman = KendallSpearman()
>>> kendall_spearman_stat = kendall_spearman.test_statistic(X, Y)
"""
assert matrix_X.shape[1] == 1, "Data matrix should be (n, 1) shape"
assert matrix_Y.shape[1] == 1, "Data matrix should be (n, 1) shape"
if self.which_test == 'kendall':
self.test_statistic_ = kendalltau(matrix_X, matrix_Y)[0]
else:
self.test_statistic_ = spearmanr(matrix_X, matrix_Y)[0]
self.test_statistic_metadata_ = {}
return self.test_statistic_, self.test_statistic_metadata_
[docs] def p_value(self, matrix_X, matrix_Y, replication_factor=1000):
"""
Tests independence between two datasets using the independence test.
:param matrix_X: a [n*p] data matrix, a matrix with n samples in p dimensions
:type matrix_X: 2D `numpy.array`
:param matrix_Y: a [n*q] data matrix, a matrix with n samples in q dimensions
:type matrix_Y: 2D `numpy.array`
:param replication_factor: specifies the number of replications to use for
the permutation test. Defaults to 1000.
:type replication_factor: int
:return: returns a list of two items, that contains:
- :p_value_: P-value
- :p_value_metadata_: (optional) a ``dict`` of metadata other than the p_value,
that the independence tests computes in the process
:rtype: float, dict
**Example:**
>>> import numpy as np
>>> from mgcpy.independence_tests.kendall_spearman import KendallSpearman
>>> X = np.array([0.07487683, -0.18073412, 0.37266440, 0.06074847, 0.76899045,
0.51862516, -0.13480764, -0.54368083, -0.73812644, 0.54910974]).reshape(-1, 1)
>>> Y = np.array([-1.31741173, -0.41634224, 2.24021815, 0.88317196, 2.00149312,
1.35857623, -0.06729464, 0.16168344, -0.61048226, 0.41711113]).reshape(-1, 1)
>>> kendall_spearman = KendallSpearman()
>>> kendall_spearman_p_value = kendall_spearman.p_value(X, Y)
"""
return super(KendallSpearman, self).p_value(matrix_X, matrix_Y)