projektAI/venv/Lib/site-packages/scipy/stats/tests/test_kdeoth.py
2021-06-06 22:13:05 +02:00

488 lines
16 KiB
Python

from scipy import stats
import numpy as np
from numpy.testing import (assert_almost_equal, assert_,
assert_array_almost_equal, assert_array_almost_equal_nulp, assert_allclose)
import pytest
from pytest import raises as assert_raises
def test_kde_1d():
#some basic tests comparing to normal distribution
np.random.seed(8765678)
n_basesample = 500
xn = np.random.randn(n_basesample)
xnmean = xn.mean()
xnstd = xn.std(ddof=1)
# get kde for original sample
gkde = stats.gaussian_kde(xn)
# evaluate the density function for the kde for some points
xs = np.linspace(-7,7,501)
kdepdf = gkde.evaluate(xs)
normpdf = stats.norm.pdf(xs, loc=xnmean, scale=xnstd)
intervall = xs[1] - xs[0]
assert_(np.sum((kdepdf - normpdf)**2)*intervall < 0.01)
prob1 = gkde.integrate_box_1d(xnmean, np.inf)
prob2 = gkde.integrate_box_1d(-np.inf, xnmean)
assert_almost_equal(prob1, 0.5, decimal=1)
assert_almost_equal(prob2, 0.5, decimal=1)
assert_almost_equal(gkde.integrate_box(xnmean, np.inf), prob1, decimal=13)
assert_almost_equal(gkde.integrate_box(-np.inf, xnmean), prob2, decimal=13)
assert_almost_equal(gkde.integrate_kde(gkde),
(kdepdf**2).sum()*intervall, decimal=2)
assert_almost_equal(gkde.integrate_gaussian(xnmean, xnstd**2),
(kdepdf*normpdf).sum()*intervall, decimal=2)
def test_kde_1d_weighted():
#some basic tests comparing to normal distribution
np.random.seed(8765678)
n_basesample = 500
xn = np.random.randn(n_basesample)
wn = np.random.rand(n_basesample)
xnmean = np.average(xn, weights=wn)
xnstd = np.sqrt(np.average((xn-xnmean)**2, weights=wn))
# get kde for original sample
gkde = stats.gaussian_kde(xn, weights=wn)
# evaluate the density function for the kde for some points
xs = np.linspace(-7,7,501)
kdepdf = gkde.evaluate(xs)
normpdf = stats.norm.pdf(xs, loc=xnmean, scale=xnstd)
intervall = xs[1] - xs[0]
assert_(np.sum((kdepdf - normpdf)**2)*intervall < 0.01)
prob1 = gkde.integrate_box_1d(xnmean, np.inf)
prob2 = gkde.integrate_box_1d(-np.inf, xnmean)
assert_almost_equal(prob1, 0.5, decimal=1)
assert_almost_equal(prob2, 0.5, decimal=1)
assert_almost_equal(gkde.integrate_box(xnmean, np.inf), prob1, decimal=13)
assert_almost_equal(gkde.integrate_box(-np.inf, xnmean), prob2, decimal=13)
assert_almost_equal(gkde.integrate_kde(gkde),
(kdepdf**2).sum()*intervall, decimal=2)
assert_almost_equal(gkde.integrate_gaussian(xnmean, xnstd**2),
(kdepdf*normpdf).sum()*intervall, decimal=2)
@pytest.mark.slow
def test_kde_2d():
#some basic tests comparing to normal distribution
np.random.seed(8765678)
n_basesample = 500
mean = np.array([1.0, 3.0])
covariance = np.array([[1.0, 2.0], [2.0, 6.0]])
# Need transpose (shape (2, 500)) for kde
xn = np.random.multivariate_normal(mean, covariance, size=n_basesample).T
# get kde for original sample
gkde = stats.gaussian_kde(xn)
# evaluate the density function for the kde for some points
x, y = np.mgrid[-7:7:500j, -7:7:500j]
grid_coords = np.vstack([x.ravel(), y.ravel()])
kdepdf = gkde.evaluate(grid_coords)
kdepdf = kdepdf.reshape(500, 500)
normpdf = stats.multivariate_normal.pdf(np.dstack([x, y]), mean=mean, cov=covariance)
intervall = y.ravel()[1] - y.ravel()[0]
assert_(np.sum((kdepdf - normpdf)**2) * (intervall**2) < 0.01)
small = -1e100
large = 1e100
prob1 = gkde.integrate_box([small, mean[1]], [large, large])
prob2 = gkde.integrate_box([small, small], [large, mean[1]])
assert_almost_equal(prob1, 0.5, decimal=1)
assert_almost_equal(prob2, 0.5, decimal=1)
assert_almost_equal(gkde.integrate_kde(gkde),
(kdepdf**2).sum()*(intervall**2), decimal=2)
assert_almost_equal(gkde.integrate_gaussian(mean, covariance),
(kdepdf*normpdf).sum()*(intervall**2), decimal=2)
@pytest.mark.slow
def test_kde_2d_weighted():
#some basic tests comparing to normal distribution
np.random.seed(8765678)
n_basesample = 500
mean = np.array([1.0, 3.0])
covariance = np.array([[1.0, 2.0], [2.0, 6.0]])
# Need transpose (shape (2, 500)) for kde
xn = np.random.multivariate_normal(mean, covariance, size=n_basesample).T
wn = np.random.rand(n_basesample)
# get kde for original sample
gkde = stats.gaussian_kde(xn, weights=wn)
# evaluate the density function for the kde for some points
x, y = np.mgrid[-7:7:500j, -7:7:500j]
grid_coords = np.vstack([x.ravel(), y.ravel()])
kdepdf = gkde.evaluate(grid_coords)
kdepdf = kdepdf.reshape(500, 500)
normpdf = stats.multivariate_normal.pdf(np.dstack([x, y]), mean=mean, cov=covariance)
intervall = y.ravel()[1] - y.ravel()[0]
assert_(np.sum((kdepdf - normpdf)**2) * (intervall**2) < 0.01)
small = -1e100
large = 1e100
prob1 = gkde.integrate_box([small, mean[1]], [large, large])
prob2 = gkde.integrate_box([small, small], [large, mean[1]])
assert_almost_equal(prob1, 0.5, decimal=1)
assert_almost_equal(prob2, 0.5, decimal=1)
assert_almost_equal(gkde.integrate_kde(gkde),
(kdepdf**2).sum()*(intervall**2), decimal=2)
assert_almost_equal(gkde.integrate_gaussian(mean, covariance),
(kdepdf*normpdf).sum()*(intervall**2), decimal=2)
def test_kde_bandwidth_method():
def scotts_factor(kde_obj):
"""Same as default, just check that it works."""
return np.power(kde_obj.n, -1./(kde_obj.d+4))
np.random.seed(8765678)
n_basesample = 50
xn = np.random.randn(n_basesample)
# Default
gkde = stats.gaussian_kde(xn)
# Supply a callable
gkde2 = stats.gaussian_kde(xn, bw_method=scotts_factor)
# Supply a scalar
gkde3 = stats.gaussian_kde(xn, bw_method=gkde.factor)
xs = np.linspace(-7,7,51)
kdepdf = gkde.evaluate(xs)
kdepdf2 = gkde2.evaluate(xs)
assert_almost_equal(kdepdf, kdepdf2)
kdepdf3 = gkde3.evaluate(xs)
assert_almost_equal(kdepdf, kdepdf3)
assert_raises(ValueError, stats.gaussian_kde, xn, bw_method='wrongstring')
def test_kde_bandwidth_method_weighted():
def scotts_factor(kde_obj):
"""Same as default, just check that it works."""
return np.power(kde_obj.neff, -1./(kde_obj.d+4))
np.random.seed(8765678)
n_basesample = 50
xn = np.random.randn(n_basesample)
# Default
gkde = stats.gaussian_kde(xn)
# Supply a callable
gkde2 = stats.gaussian_kde(xn, bw_method=scotts_factor)
# Supply a scalar
gkde3 = stats.gaussian_kde(xn, bw_method=gkde.factor)
xs = np.linspace(-7,7,51)
kdepdf = gkde.evaluate(xs)
kdepdf2 = gkde2.evaluate(xs)
assert_almost_equal(kdepdf, kdepdf2)
kdepdf3 = gkde3.evaluate(xs)
assert_almost_equal(kdepdf, kdepdf3)
assert_raises(ValueError, stats.gaussian_kde, xn, bw_method='wrongstring')
# Subclasses that should stay working (extracted from various sources).
# Unfortunately the earlier design of gaussian_kde made it necessary for users
# to create these kinds of subclasses, or call _compute_covariance() directly.
class _kde_subclass1(stats.gaussian_kde):
def __init__(self, dataset):
self.dataset = np.atleast_2d(dataset)
self.d, self.n = self.dataset.shape
self.covariance_factor = self.scotts_factor
self._compute_covariance()
class _kde_subclass2(stats.gaussian_kde):
def __init__(self, dataset):
self.covariance_factor = self.scotts_factor
super(_kde_subclass2, self).__init__(dataset)
class _kde_subclass3(stats.gaussian_kde):
def __init__(self, dataset, covariance):
self.covariance = covariance
stats.gaussian_kde.__init__(self, dataset)
def _compute_covariance(self):
self.inv_cov = np.linalg.inv(self.covariance)
self._norm_factor = np.sqrt(np.linalg.det(2 * np.pi * self.covariance))
class _kde_subclass4(stats.gaussian_kde):
def covariance_factor(self):
return 0.5 * self.silverman_factor()
def test_gaussian_kde_subclassing():
x1 = np.array([-7, -5, 1, 4, 5], dtype=float)
xs = np.linspace(-10, 10, num=50)
# gaussian_kde itself
kde = stats.gaussian_kde(x1)
ys = kde(xs)
# subclass 1
kde1 = _kde_subclass1(x1)
y1 = kde1(xs)
assert_array_almost_equal_nulp(ys, y1, nulp=10)
# subclass 2
kde2 = _kde_subclass2(x1)
y2 = kde2(xs)
assert_array_almost_equal_nulp(ys, y2, nulp=10)
# subclass 3
kde3 = _kde_subclass3(x1, kde.covariance)
y3 = kde3(xs)
assert_array_almost_equal_nulp(ys, y3, nulp=10)
# subclass 4
kde4 = _kde_subclass4(x1)
y4 = kde4(x1)
y_expected = [0.06292987, 0.06346938, 0.05860291, 0.08657652, 0.07904017]
assert_array_almost_equal(y_expected, y4, decimal=6)
# Not a subclass, but check for use of _compute_covariance()
kde5 = kde
kde5.covariance_factor = lambda: kde.factor
kde5._compute_covariance()
y5 = kde5(xs)
assert_array_almost_equal_nulp(ys, y5, nulp=10)
def test_gaussian_kde_covariance_caching():
x1 = np.array([-7, -5, 1, 4, 5], dtype=float)
xs = np.linspace(-10, 10, num=5)
# These expected values are from scipy 0.10, before some changes to
# gaussian_kde. They were not compared with any external reference.
y_expected = [0.02463386, 0.04689208, 0.05395444, 0.05337754, 0.01664475]
# Set the bandwidth, then reset it to the default.
kde = stats.gaussian_kde(x1)
kde.set_bandwidth(bw_method=0.5)
kde.set_bandwidth(bw_method='scott')
y2 = kde(xs)
assert_array_almost_equal(y_expected, y2, decimal=7)
def test_gaussian_kde_monkeypatch():
"""Ugly, but people may rely on this. See scipy pull request 123,
specifically the linked ML thread "Width of the Gaussian in stats.kde".
If it is necessary to break this later on, that is to be discussed on ML.
"""
x1 = np.array([-7, -5, 1, 4, 5], dtype=float)
xs = np.linspace(-10, 10, num=50)
# The old monkeypatched version to get at Silverman's Rule.
kde = stats.gaussian_kde(x1)
kde.covariance_factor = kde.silverman_factor
kde._compute_covariance()
y1 = kde(xs)
# The new saner version.
kde2 = stats.gaussian_kde(x1, bw_method='silverman')
y2 = kde2(xs)
assert_array_almost_equal_nulp(y1, y2, nulp=10)
def test_kde_integer_input():
"""Regression test for #1181."""
x1 = np.arange(5)
kde = stats.gaussian_kde(x1)
y_expected = [0.13480721, 0.18222869, 0.19514935, 0.18222869, 0.13480721]
assert_array_almost_equal(kde(x1), y_expected, decimal=6)
_ftypes = ['float32', 'float64', 'float96', 'float128', 'int32', 'int64']
@pytest.mark.parametrize("bw_type", _ftypes + ["scott", "silverman"])
@pytest.mark.parametrize("weights_type", _ftypes)
@pytest.mark.parametrize("dataset_type", _ftypes)
@pytest.mark.parametrize("point_type", _ftypes)
def test_kde_output_dtype(point_type, dataset_type, weights_type, bw_type):
# Check whether the datatypes are available
point_type = getattr(np, point_type, None)
dataset_type = getattr(np, weights_type, None)
weights_type = getattr(np, weights_type, None)
if bw_type in ["scott", "silverman"]:
bw = bw_type
else:
bw_type = getattr(np, bw_type, None)
bw = bw_type(3) if bw_type else None
if any(dt is None for dt in [point_type, dataset_type, weights_type, bw]):
pytest.skip()
weights = np.arange(5, dtype=weights_type)
dataset = np.arange(5, dtype=dataset_type)
k = stats.kde.gaussian_kde(dataset, bw_method=bw, weights=weights)
points = np.arange(5, dtype=point_type)
result = k(points)
# weights are always cast to float64
assert result.dtype == np.result_type(dataset, points, np.float64(weights),
k.factor)
def test_pdf_logpdf():
np.random.seed(1)
n_basesample = 50
xn = np.random.randn(n_basesample)
# Default
gkde = stats.gaussian_kde(xn)
xs = np.linspace(-15, 12, 25)
pdf = gkde.evaluate(xs)
pdf2 = gkde.pdf(xs)
assert_almost_equal(pdf, pdf2, decimal=12)
logpdf = np.log(pdf)
logpdf2 = gkde.logpdf(xs)
assert_almost_equal(logpdf, logpdf2, decimal=12)
# There are more points than data
gkde = stats.gaussian_kde(xs)
pdf = np.log(gkde.evaluate(xn))
pdf2 = gkde.logpdf(xn)
assert_almost_equal(pdf, pdf2, decimal=12)
def test_pdf_logpdf_weighted():
np.random.seed(1)
n_basesample = 50
xn = np.random.randn(n_basesample)
wn = np.random.rand(n_basesample)
# Default
gkde = stats.gaussian_kde(xn, weights=wn)
xs = np.linspace(-15, 12, 25)
pdf = gkde.evaluate(xs)
pdf2 = gkde.pdf(xs)
assert_almost_equal(pdf, pdf2, decimal=12)
logpdf = np.log(pdf)
logpdf2 = gkde.logpdf(xs)
assert_almost_equal(logpdf, logpdf2, decimal=12)
# There are more points than data
gkde = stats.gaussian_kde(xs, weights=np.random.rand(len(xs)))
pdf = np.log(gkde.evaluate(xn))
pdf2 = gkde.logpdf(xn)
assert_almost_equal(pdf, pdf2, decimal=12)
def test_logpdf_overflow():
# regression test for gh-12988; testing against linalg instability for
# very high dimensionality kde
np.random.seed(1)
n_dimensions = 2500
n_samples = 5000
xn = np.array([np.random.randn(n_samples) + (n) for n in range(
0, n_dimensions)])
# Default
gkde = stats.gaussian_kde(xn)
logpdf = gkde.logpdf(np.arange(0, n_dimensions))
np.testing.assert_equal(np.isneginf(logpdf[0]), False)
np.testing.assert_equal(np.isnan(logpdf[0]), False)
def test_weights_intact():
# regression test for gh-9709: weights are not modified
np.random.seed(12345)
vals = np.random.lognormal(size=100)
weights = np.random.choice([1.0, 10.0, 100], size=vals.size)
orig_weights = weights.copy()
stats.gaussian_kde(np.log10(vals), weights=weights)
assert_allclose(weights, orig_weights, atol=1e-14, rtol=1e-14)
def test_weights_integer():
# integer weights are OK, cf gh-9709 (comment)
np.random.seed(12345)
values = [0.2, 13.5, 21.0, 75.0, 99.0]
weights = [1, 2, 4, 8, 16] # a list of integers
pdf_i = stats.gaussian_kde(values, weights=weights)
pdf_f = stats.gaussian_kde(values, weights=np.float64(weights))
xn = [0.3, 11, 88]
assert_allclose(pdf_i.evaluate(xn),
pdf_f.evaluate(xn), atol=1e-14, rtol=1e-14)
def test_seed():
# Test the seed option of the resample method
def test_seed_sub(gkde_trail):
n_sample = 200
# The results should be different without using seed
samp1 = gkde_trail.resample(n_sample)
samp2 = gkde_trail.resample(n_sample)
assert_raises(
AssertionError, assert_allclose, samp1, samp2, atol=1e-13
)
# Use integer seed
seed = 831
samp1 = gkde_trail.resample(n_sample, seed=seed)
samp2 = gkde_trail.resample(n_sample, seed=seed)
assert_allclose(samp1, samp2, atol=1e-13)
# Use RandomState
rstate1 = np.random.RandomState(seed=138)
samp1 = gkde_trail.resample(n_sample, seed=rstate1)
rstate2 = np.random.RandomState(seed=138)
samp2 = gkde_trail.resample(n_sample, seed=rstate2)
assert_allclose(samp1, samp2, atol=1e-13)
# check that np.random.Generator can be used (numpy >= 1.17)
if hasattr(np.random, 'default_rng'):
# obtain a np.random.Generator object
rng = np.random.default_rng(1234)
gkde_trail.resample(n_sample, seed=rng)
np.random.seed(8765678)
n_basesample = 500
wn = np.random.rand(n_basesample)
# Test 1D case
xn_1d = np.random.randn(n_basesample)
gkde_1d = stats.gaussian_kde(xn_1d)
test_seed_sub(gkde_1d)
gkde_1d_weighted = stats.gaussian_kde(xn_1d, weights=wn)
test_seed_sub(gkde_1d_weighted)
# Test 2D case
mean = np.array([1.0, 3.0])
covariance = np.array([[1.0, 2.0], [2.0, 6.0]])
xn_2d = np.random.multivariate_normal(mean, covariance, size=n_basesample).T
gkde_2d = stats.gaussian_kde(xn_2d)
test_seed_sub(gkde_2d)
gkde_2d_weighted = stats.gaussian_kde(xn_2d, weights=wn)
test_seed_sub(gkde_2d_weighted)