craftbeerpi4-pione/venv3/lib/python3.7/site-packages/pandas/tests/window/common.py
2021-03-03 23:49:41 +01:00

189 lines
6 KiB
Python

import numpy as np
from pandas import Series
import pandas._testing as tm
def check_pairwise_moment(frame, dispatch, name, **kwargs):
def get_result(obj, obj2=None):
return getattr(getattr(obj, dispatch)(**kwargs), name)(obj2)
result = get_result(frame)
result = result.loc[(slice(None), 1), 5]
result.index = result.index.droplevel(1)
expected = get_result(frame[1], frame[5])
tm.assert_series_equal(result, expected, check_names=False)
def ew_func(A, B, com, name, **kwargs):
return getattr(A.ewm(com, **kwargs), name)(B)
def check_binary_ew(name, A, B):
result = ew_func(A=A, B=B, com=20, name=name, min_periods=5)
assert np.isnan(result.values[:14]).all()
assert not np.isnan(result.values[14:]).any()
def check_binary_ew_min_periods(name, min_periods, A, B):
# GH 7898
result = ew_func(A, B, 20, name=name, min_periods=min_periods)
# binary functions (ewmcov, ewmcorr) with bias=False require at
# least two values
assert np.isnan(result.values[:11]).all()
assert not np.isnan(result.values[11:]).any()
# check series of length 0
empty = Series([], dtype=np.float64)
result = ew_func(empty, empty, 50, name=name, min_periods=min_periods)
tm.assert_series_equal(result, empty)
# check series of length 1
result = ew_func(
Series([1.0]), Series([1.0]), 50, name=name, min_periods=min_periods
)
tm.assert_series_equal(result, Series([np.NaN]))
def moments_consistency_mock_mean(x, mean, mock_mean):
mean_x = mean(x)
# check that correlation of a series with itself is either 1 or NaN
if mock_mean:
# check that mean equals mock_mean
expected = mock_mean(x)
tm.assert_equal(mean_x, expected.astype("float64"))
def moments_consistency_is_constant(x, is_constant, min_periods, count, mean, corr):
count_x = count(x)
mean_x = mean(x)
# check that correlation of a series with itself is either 1 or NaN
corr_x_x = corr(x, x)
if is_constant:
exp = x.max() if isinstance(x, Series) else x.max().max()
# check mean of constant series
expected = x * np.nan
expected[count_x >= max(min_periods, 1)] = exp
tm.assert_equal(mean_x, expected)
# check correlation of constant series with itself is NaN
expected[:] = np.nan
tm.assert_equal(corr_x_x, expected)
def moments_consistency_var_debiasing_factors(
x, var_biased, var_unbiased, var_debiasing_factors
):
if var_unbiased and var_biased and var_debiasing_factors:
# check variance debiasing factors
var_unbiased_x = var_unbiased(x)
var_biased_x = var_biased(x)
var_debiasing_factors_x = var_debiasing_factors(x)
tm.assert_equal(var_unbiased_x, var_biased_x * var_debiasing_factors_x)
def moments_consistency_var_data(
x, is_constant, min_periods, count, mean, var_unbiased, var_biased
):
count_x = count(x)
mean_x = mean(x)
for var in [var_biased, var_unbiased]:
var_x = var(x)
assert not (var_x < 0).any().any()
if var is var_biased:
# check that biased var(x) == mean(x^2) - mean(x)^2
mean_x2 = mean(x * x)
tm.assert_equal(var_x, mean_x2 - (mean_x * mean_x))
if is_constant:
# check that variance of constant series is identically 0
assert not (var_x > 0).any().any()
expected = x * np.nan
expected[count_x >= max(min_periods, 1)] = 0.0
if var is var_unbiased:
expected[count_x < 2] = np.nan
tm.assert_equal(var_x, expected)
def moments_consistency_std_data(x, std_unbiased, var_unbiased, std_biased, var_biased):
for (std, var) in [(std_biased, var_biased), (std_unbiased, var_unbiased)]:
var_x = var(x)
std_x = std(x)
assert not (var_x < 0).any().any()
assert not (std_x < 0).any().any()
# check that var(x) == std(x)^2
tm.assert_equal(var_x, std_x * std_x)
def moments_consistency_cov_data(x, cov_unbiased, var_unbiased, cov_biased, var_biased):
for (cov, var) in [(cov_biased, var_biased), (cov_unbiased, var_unbiased)]:
var_x = var(x)
assert not (var_x < 0).any().any()
if cov:
cov_x_x = cov(x, x)
assert not (cov_x_x < 0).any().any()
# check that var(x) == cov(x, x)
tm.assert_equal(var_x, cov_x_x)
def moments_consistency_series_data(
x,
corr,
mean,
std_biased,
std_unbiased,
cov_unbiased,
var_unbiased,
var_biased,
cov_biased,
):
if isinstance(x, Series):
y = x
mean_x = mean(x)
if not x.isna().equals(y.isna()):
# can only easily test two Series with similar
# structure
pass
# check that cor(x, y) is symmetric
corr_x_y = corr(x, y)
corr_y_x = corr(y, x)
tm.assert_equal(corr_x_y, corr_y_x)
for (std, var, cov) in [
(std_biased, var_biased, cov_biased),
(std_unbiased, var_unbiased, cov_unbiased),
]:
var_x = var(x)
std_x = std(x)
if cov:
# check that cov(x, y) is symmetric
cov_x_y = cov(x, y)
cov_y_x = cov(y, x)
tm.assert_equal(cov_x_y, cov_y_x)
# check that cov(x, y) == (var(x+y) - var(x) -
# var(y)) / 2
var_x_plus_y = var(x + y)
var_y = var(y)
tm.assert_equal(cov_x_y, 0.5 * (var_x_plus_y - var_x - var_y))
# check that corr(x, y) == cov(x, y) / (std(x) *
# std(y))
std_y = std(y)
tm.assert_equal(corr_x_y, cov_x_y / (std_x * std_y))
if cov is cov_biased:
# check that biased cov(x, y) == mean(x*y) -
# mean(x)*mean(y)
mean_y = mean(y)
mean_x_times_y = mean(x * y)
tm.assert_equal(cov_x_y, mean_x_times_y - (mean_x * mean_y))