AIM-PIbd-32-Kurbanova-A-A/aimenv/Lib/site-packages/statsmodels/regression/tests/test_lme.py
2024-10-02 22:15:59 +04:00

1348 lines
45 KiB
Python

from statsmodels.compat.platform import PLATFORM_OSX
import os
import csv
import warnings
import numpy as np
import pandas as pd
from scipy import sparse
import pytest
from statsmodels.regression.mixed_linear_model import (
MixedLM, MixedLMParams, _smw_solver, _smw_logdet)
from numpy.testing import (assert_almost_equal, assert_equal, assert_allclose,
assert_)
from statsmodels.base import _penalties as penalties
import statsmodels.tools.numdiff as nd
from .results import lme_r_results
# TODO: add tests with unequal group sizes
class R_Results:
"""
A class for holding various results obtained from fitting one data
set using lmer in R.
Parameters
----------
meth : str
Either "ml" or "reml".
irfs : str
Either "irf", for independent random effects, or "drf" for
dependent random effects.
ds_ix : int
The number of the data set
"""
def __init__(self, meth, irfs, ds_ix):
bname = "_%s_%s_%d" % (meth, irfs, ds_ix)
self.coef = getattr(lme_r_results, "coef" + bname)
self.vcov_r = getattr(lme_r_results, "vcov" + bname)
self.cov_re_r = getattr(lme_r_results, "cov_re" + bname)
self.scale_r = getattr(lme_r_results, "scale" + bname)
self.loglike = getattr(lme_r_results, "loglike" + bname)
if hasattr(lme_r_results, "ranef_mean" + bname):
self.ranef_postmean = getattr(lme_r_results, "ranef_mean" + bname)
self.ranef_condvar = getattr(lme_r_results,
"ranef_condvar" + bname)
self.ranef_condvar = np.atleast_2d(self.ranef_condvar)
# Load the data file
cur_dir = os.path.dirname(os.path.abspath(__file__))
rdir = os.path.join(cur_dir, 'results')
fname = os.path.join(rdir, "lme%02d.csv" % ds_ix)
with open(fname, encoding="utf-8") as fid:
rdr = csv.reader(fid)
header = next(rdr)
data = [[float(x) for x in line] for line in rdr]
data = np.asarray(data)
# Split into exog, endog, etc.
self.endog = data[:, header.index("endog")]
self.groups = data[:, header.index("groups")]
ii = [i for i, x in enumerate(header) if x.startswith("exog_fe")]
self.exog_fe = data[:, ii]
ii = [i for i, x in enumerate(header) if x.startswith("exog_re")]
self.exog_re = data[:, ii]
def loglike_function(model, profile_fe, has_fe):
# Returns a function that evaluates the negative log-likelihood for
# the given model.
def f(x):
params = MixedLMParams.from_packed(
x, model.k_fe, model.k_re, model.use_sqrt, has_fe=has_fe)
return -model.loglike(params, profile_fe=profile_fe)
return f
class TestMixedLM:
# Test analytic scores and Hessian using numeric differentiation
@pytest.mark.slow
@pytest.mark.parametrize("use_sqrt", [False, True])
@pytest.mark.parametrize("reml", [False, True])
@pytest.mark.parametrize("profile_fe", [False, True])
def test_compare_numdiff(self, use_sqrt, reml, profile_fe):
n_grp = 200
grpsize = 5
k_fe = 3
k_re = 2
np.random.seed(3558)
exog_fe = np.random.normal(size=(n_grp * grpsize, k_fe))
exog_re = np.random.normal(size=(n_grp * grpsize, k_re))
exog_re[:, 0] = 1
exog_vc = np.random.normal(size=(n_grp * grpsize, 3))
slopes = np.random.normal(size=(n_grp, k_re))
slopes[:, -1] *= 2
slopes = np.kron(slopes, np.ones((grpsize, 1)))
slopes_vc = np.random.normal(size=(n_grp, 3))
slopes_vc = np.kron(slopes_vc, np.ones((grpsize, 1)))
slopes_vc[:, -1] *= 2
re_values = (slopes * exog_re).sum(1)
vc_values = (slopes_vc * exog_vc).sum(1)
err = np.random.normal(size=n_grp * grpsize)
endog = exog_fe.sum(1) + re_values + vc_values + err
groups = np.kron(range(n_grp), np.ones(grpsize))
vc = {"a": {}, "b": {}}
for i in range(n_grp):
ix = np.flatnonzero(groups == i)
vc["a"][i] = exog_vc[ix, 0:2]
vc["b"][i] = exog_vc[ix, 2:3]
with pytest.warns(UserWarning, match="Using deprecated variance"):
model = MixedLM(
endog,
exog_fe,
groups,
exog_re,
exog_vc=vc,
use_sqrt=use_sqrt)
rslt = model.fit(reml=reml)
loglike = loglike_function(
model, profile_fe=profile_fe, has_fe=not profile_fe)
try:
# Test the score at several points.
for kr in range(5):
fe_params = np.random.normal(size=k_fe)
cov_re = np.random.normal(size=(k_re, k_re))
cov_re = np.dot(cov_re.T, cov_re)
vcomp = np.random.normal(size=2)**2
params = MixedLMParams.from_components(
fe_params, cov_re=cov_re, vcomp=vcomp)
params_vec = params.get_packed(
has_fe=not profile_fe, use_sqrt=use_sqrt)
# Check scores
gr = -model.score(params, profile_fe=profile_fe)
ngr = nd.approx_fprime(params_vec, loglike)
assert_allclose(gr, ngr, rtol=1e-3)
# Check Hessian matrices at the MLE (we do not have
# the profile Hessian matrix and we do not care
# about the Hessian for the square root
# transformed parameter).
if (profile_fe is False) and (use_sqrt is False):
hess, sing = model.hessian(rslt.params_object)
if sing:
pytest.fail("hessian should not be singular")
hess *= -1
params_vec = rslt.params_object.get_packed(
use_sqrt=False, has_fe=True)
loglike_h = loglike_function(
model, profile_fe=False, has_fe=True)
nhess = nd.approx_hess(params_vec, loglike_h)
assert_allclose(hess, nhess, rtol=1e-3)
except AssertionError:
# See GH#5628; because this test fails unpredictably but only on
# OSX, we only xfail it there.
if PLATFORM_OSX:
pytest.xfail("fails on OSX due to unresolved "
"numerical differences")
else:
raise
def test_default_re(self):
np.random.seed(3235)
exog = np.random.normal(size=(300, 4))
groups = np.kron(np.arange(100), [1, 1, 1])
g_errors = np.kron(np.random.normal(size=100), [1, 1, 1])
endog = exog.sum(1) + g_errors + np.random.normal(size=300)
mdf1 = MixedLM(endog, exog, groups).fit()
mdf2 = MixedLM(endog, exog, groups, np.ones(300)).fit()
assert_almost_equal(mdf1.params, mdf2.params, decimal=8)
def test_history(self):
np.random.seed(3235)
exog = np.random.normal(size=(300, 4))
groups = np.kron(np.arange(100), [1, 1, 1])
g_errors = np.kron(np.random.normal(size=100), [1, 1, 1])
endog = exog.sum(1) + g_errors + np.random.normal(size=300)
mod = MixedLM(endog, exog, groups)
rslt = mod.fit(full_output=True)
assert_equal(hasattr(rslt, "hist"), True)
@pytest.mark.slow
@pytest.mark.smoke
def test_profile_inference(self):
np.random.seed(9814)
k_fe = 2
gsize = 3
n_grp = 100
exog = np.random.normal(size=(n_grp * gsize, k_fe))
exog_re = np.ones((n_grp * gsize, 1))
groups = np.kron(np.arange(n_grp), np.ones(gsize))
vca = np.random.normal(size=n_grp * gsize)
vcb = np.random.normal(size=n_grp * gsize)
errors = 0
g_errors = np.kron(np.random.normal(size=100), np.ones(gsize))
errors += g_errors + exog_re[:, 0]
rc = np.random.normal(size=n_grp)
errors += np.kron(rc, np.ones(gsize)) * vca
rc = np.random.normal(size=n_grp)
errors += np.kron(rc, np.ones(gsize)) * vcb
errors += np.random.normal(size=n_grp * gsize)
endog = exog.sum(1) + errors
vc = {"a": {}, "b": {}}
for k in range(n_grp):
ii = np.flatnonzero(groups == k)
vc["a"][k] = vca[ii][:, None]
vc["b"][k] = vcb[ii][:, None]
with pytest.warns(UserWarning, match="Using deprecated variance"):
rslt = MixedLM(endog, exog, groups=groups,
exog_re=exog_re, exog_vc=vc).fit()
rslt.profile_re(0, vtype='re', dist_low=1, num_low=3,
dist_high=1, num_high=3)
rslt.profile_re('b', vtype='vc', dist_low=0.5, num_low=3,
dist_high=0.5, num_high=3)
def test_vcomp_1(self):
# Fit the same model using constrained random effects and
# variance components.
np.random.seed(4279)
exog = np.random.normal(size=(400, 1))
exog_re = np.random.normal(size=(400, 2))
groups = np.kron(np.arange(100), np.ones(4))
slopes = np.random.normal(size=(100, 2))
slopes[:, 1] *= 2
slopes = np.kron(slopes, np.ones((4, 1))) * exog_re
errors = slopes.sum(1) + np.random.normal(size=400)
endog = exog.sum(1) + errors
free = MixedLMParams(1, 2, 0)
free.fe_params = np.ones(1)
free.cov_re = np.eye(2)
free.vcomp = np.zeros(0)
model1 = MixedLM(endog, exog, groups, exog_re=exog_re)
result1 = model1.fit(free=free)
exog_vc = {"a": {}, "b": {}}
for k, group in enumerate(model1.group_labels):
ix = model1.row_indices[group]
exog_vc["a"][group] = exog_re[ix, 0:1]
exog_vc["b"][group] = exog_re[ix, 1:2]
with pytest.warns(UserWarning, match="Using deprecated variance"):
model2 = MixedLM(endog, exog, groups, exog_vc=exog_vc)
result2 = model2.fit()
result2.summary()
assert_allclose(result1.fe_params, result2.fe_params, atol=1e-4)
assert_allclose(
np.diag(result1.cov_re), result2.vcomp, atol=1e-2, rtol=1e-4)
assert_allclose(
result1.bse[[0, 1, 3]], result2.bse, atol=1e-2, rtol=1e-2)
def test_vcomp_2(self):
# Simulated data comparison to R
np.random.seed(6241)
n = 1600
exog = np.random.normal(size=(n, 2))
groups = np.kron(np.arange(n / 16), np.ones(16))
# Build up the random error vector
errors = 0
# The random effects
exog_re = np.random.normal(size=(n, 2))
slopes = np.random.normal(size=(n // 16, 2))
slopes = np.kron(slopes, np.ones((16, 1))) * exog_re
errors += slopes.sum(1)
# First variance component
subgroups1 = np.kron(np.arange(n / 4), np.ones(4))
errors += np.kron(2 * np.random.normal(size=n // 4), np.ones(4))
# Second variance component
subgroups2 = np.kron(np.arange(n / 2), np.ones(2))
errors += np.kron(2 * np.random.normal(size=n // 2), np.ones(2))
# iid errors
errors += np.random.normal(size=n)
endog = exog.sum(1) + errors
df = pd.DataFrame(index=range(n))
df["y"] = endog
df["groups"] = groups
df["x1"] = exog[:, 0]
df["x2"] = exog[:, 1]
df["z1"] = exog_re[:, 0]
df["z2"] = exog_re[:, 1]
df["v1"] = subgroups1
df["v2"] = subgroups2
# Equivalent model in R:
# df.to_csv("tst.csv")
# model = lmer(y ~ x1 + x2 + (0 + z1 + z2 | groups) + (1 | v1) + (1 |
# v2), df)
vcf = {"a": "0 + C(v1)", "b": "0 + C(v2)"}
model1 = MixedLM.from_formula(
"y ~ x1 + x2",
groups=groups,
re_formula="0+z1+z2",
vc_formula=vcf,
data=df)
result1 = model1.fit()
# Compare to R
assert_allclose(
result1.fe_params, [0.16527, 0.99911, 0.96217], rtol=1e-4)
assert_allclose(
result1.cov_re, [[1.244, 0.146], [0.146, 1.371]], rtol=1e-3)
assert_allclose(result1.vcomp, [4.024, 3.997], rtol=1e-3)
assert_allclose(
result1.bse.iloc[0:3], [0.12610, 0.03938, 0.03848], rtol=1e-3)
def test_vcomp_3(self):
# Test a model with vcomp but no other random effects, using formulas.
np.random.seed(4279)
x1 = np.random.normal(size=400)
groups = np.kron(np.arange(100), np.ones(4))
slopes = np.random.normal(size=100)
slopes = np.kron(slopes, np.ones(4)) * x1
y = slopes + np.random.normal(size=400)
vc_fml = {"a": "0 + x1"}
df = pd.DataFrame({"y": y, "x1": x1, "groups": groups})
model = MixedLM.from_formula(
"y ~ 1", groups="groups", vc_formula=vc_fml, data=df)
result = model.fit()
result.summary()
assert_allclose(
result.resid.iloc[0:4],
np.r_[-1.180753, 0.279966, 0.578576, -0.667916],
rtol=1e-3)
assert_allclose(
result.fittedvalues.iloc[0:4],
np.r_[-0.101549, 0.028613, -0.224621, -0.126295],
rtol=1e-3)
def test_sparse(self):
cur_dir = os.path.dirname(os.path.abspath(__file__))
rdir = os.path.join(cur_dir, 'results')
fname = os.path.join(rdir, 'pastes.csv')
# Dense
data = pd.read_csv(fname)
vcf = {"cask": "0 + cask"}
model = MixedLM.from_formula(
"strength ~ 1",
groups="batch",
re_formula="1",
vc_formula=vcf,
data=data)
result = model.fit()
# Sparse
model2 = MixedLM.from_formula(
"strength ~ 1",
groups="batch",
re_formula="1",
vc_formula=vcf,
use_sparse=True,
data=data)
result2 = model2.fit()
assert_allclose(result.params, result2.params)
assert_allclose(result.bse, result2.bse)
def test_dietox(self):
# dietox data from geepack using random intercepts
#
# Fit in R using
#
# library(geepack)
# rm = lmer(Weight ~ Time + (1 | Pig), data=dietox)
# rm = lmer(Weight ~ Time + (1 | Pig), REML=FALSE, data=dietox)
#
# Comments below are R code used to extract the numbers used
# for comparison.
cur_dir = os.path.dirname(os.path.abspath(__file__))
rdir = os.path.join(cur_dir, 'results')
fname = os.path.join(rdir, 'dietox.csv')
# REML
data = pd.read_csv(fname)
model = MixedLM.from_formula("Weight ~ Time", groups="Pig", data=data)
result = model.fit()
# fixef(rm)
assert_allclose(
result.fe_params, np.r_[15.723523, 6.942505], rtol=1e-5)
# sqrt(diag(vcov(rm)))
assert_allclose(
result.bse[0:2], np.r_[0.78805374, 0.03338727], rtol=1e-5)
# attr(VarCorr(rm), "sc")^2
assert_allclose(result.scale, 11.36692, rtol=1e-5)
# VarCorr(rm)[[1]][[1]]
assert_allclose(result.cov_re, 40.39395, rtol=1e-5)
# logLik(rm)
assert_allclose(
model.loglike(result.params_object), -2404.775, rtol=1e-5)
# ML
data = pd.read_csv(fname)
model = MixedLM.from_formula("Weight ~ Time", groups="Pig", data=data)
result = model.fit(reml=False)
# fixef(rm)
assert_allclose(
result.fe_params, np.r_[15.723517, 6.942506], rtol=1e-5)
# sqrt(diag(vcov(rm)))
assert_allclose(
result.bse[0:2], np.r_[0.7829397, 0.0333661], rtol=1e-5)
# attr(VarCorr(rm), "sc")^2
assert_allclose(result.scale, 11.35251, rtol=1e-5)
# VarCorr(rm)[[1]][[1]]
assert_allclose(result.cov_re, 39.82097, rtol=1e-5)
# logLik(rm)
assert_allclose(
model.loglike(result.params_object), -2402.932, rtol=1e-5)
def test_dietox_slopes(self):
# dietox data from geepack using random intercepts
#
# Fit in R using
#
# library(geepack)
# r = lmer(Weight ~ Time + (1 + Time | Pig), data=dietox)
# r = lmer(Weight ~ Time + (1 + Time | Pig), REML=FALSE, data=dietox)
#
# Comments below are the R code used to extract the constants
# for comparison.
cur_dir = os.path.dirname(os.path.abspath(__file__))
rdir = os.path.join(cur_dir, 'results')
fname = os.path.join(rdir, 'dietox.csv')
# REML
data = pd.read_csv(fname)
model = MixedLM.from_formula(
"Weight ~ Time", groups="Pig", re_formula="1 + Time", data=data)
result = model.fit(method="cg")
# fixef(r)
assert_allclose(
result.fe_params, np.r_[15.738650, 6.939014], rtol=1e-5)
# sqrt(diag(vcov(r)))
assert_allclose(
result.bse[0:2], np.r_[0.5501253, 0.0798254], rtol=1e-3)
# attr(VarCorr(r), "sc")^2
assert_allclose(result.scale, 6.03745, rtol=1e-3)
# as.numeric(VarCorr(r)[[1]])
assert_allclose(
result.cov_re.values.ravel(),
np.r_[19.4934552, 0.2938323, 0.2938323, 0.4160620],
rtol=1e-1)
# logLik(r)
assert_allclose(
model.loglike(result.params_object), -2217.047, rtol=1e-5)
# ML
data = pd.read_csv(fname)
model = MixedLM.from_formula(
"Weight ~ Time", groups="Pig", re_formula="1 + Time", data=data)
result = model.fit(method='cg', reml=False)
# fixef(r)
assert_allclose(result.fe_params, np.r_[15.73863, 6.93902], rtol=1e-5)
# sqrt(diag(vcov(r)))
assert_allclose(
result.bse[0:2], np.r_[0.54629282, 0.07926954], rtol=1e-3)
# attr(VarCorr(r), "sc")^2
assert_allclose(result.scale, 6.037441, rtol=1e-3)
# as.numeric(VarCorr(r)[[1]])
assert_allclose(
result.cov_re.values.ravel(),
np.r_[19.190922, 0.293568, 0.293568, 0.409695],
rtol=1e-2)
# logLik(r)
assert_allclose(
model.loglike(result.params_object), -2215.753, rtol=1e-5)
def test_pastes_vcomp(self):
# pastes data from lme4
#
# Fit in R using:
#
# r = lmer(strength ~ (1|batch) + (1|batch:cask), data=data)
# r = lmer(strength ~ (1|batch) + (1|batch:cask), data=data,
# reml=FALSE)
cur_dir = os.path.dirname(os.path.abspath(__file__))
rdir = os.path.join(cur_dir, 'results')
fname = os.path.join(rdir, 'pastes.csv')
data = pd.read_csv(fname)
vcf = {"cask": "0 + cask"}
# REML
model = MixedLM.from_formula(
"strength ~ 1",
groups="batch",
re_formula="1",
vc_formula=vcf,
data=data)
result = model.fit()
# fixef(r)
assert_allclose(result.fe_params.iloc[0], 60.0533, rtol=1e-3)
# sqrt(diag(vcov(r)))
assert_allclose(result.bse.iloc[0], 0.6769, rtol=1e-3)
# VarCorr(r)$batch[[1]]
assert_allclose(result.cov_re.iloc[0, 0], 1.657, rtol=1e-3)
# attr(VarCorr(r), "sc")^2
assert_allclose(result.scale, 0.678, rtol=1e-3)
# logLik(r)
assert_allclose(result.llf, -123.49, rtol=1e-1)
# do not provide aic/bic with REML
assert_equal(result.aic, np.nan)
assert_equal(result.bic, np.nan)
# resid(r)[1:5]
resid = np.r_[0.17133538, -0.02866462, -1.08662875, 1.11337125,
-0.12093607]
assert_allclose(result.resid[0:5], resid, rtol=1e-3)
# predict(r)[1:5]
fit = np.r_[62.62866, 62.62866, 61.18663, 61.18663, 62.82094]
assert_allclose(result.fittedvalues[0:5], fit, rtol=1e-4)
# ML
model = MixedLM.from_formula(
"strength ~ 1",
groups="batch",
re_formula="1",
vc_formula=vcf,
data=data)
result = model.fit(reml=False)
# fixef(r)
assert_allclose(result.fe_params.iloc[0], 60.0533, rtol=1e-3)
# sqrt(diag(vcov(r)))
assert_allclose(result.bse.iloc[0], 0.642, rtol=1e-3)
# VarCorr(r)$batch[[1]]
assert_allclose(result.cov_re.iloc[0, 0], 1.199, rtol=1e-3)
# attr(VarCorr(r), "sc")^2
assert_allclose(result.scale, 0.67799, rtol=1e-3)
# logLik(r)
assert_allclose(result.llf, -123.997, rtol=1e-1)
# AIC(r)
assert_allclose(result.aic, 255.9944, rtol=1e-3)
# BIC(r)
assert_allclose(result.bic, 264.3718, rtol=1e-3)
@pytest.mark.slow
def test_vcomp_formula(self):
np.random.seed(6241)
n = 800
exog = np.random.normal(size=(n, 2))
exog[:, 0] = 1
ex_vc = []
groups = np.kron(np.arange(n / 4), np.ones(4))
errors = 0
exog_re = np.random.normal(size=(n, 2))
slopes = np.random.normal(size=(n // 4, 2))
slopes = np.kron(slopes, np.ones((4, 1))) * exog_re
errors += slopes.sum(1)
ex_vc = np.random.normal(size=(n, 4))
slopes = np.random.normal(size=(n // 4, 4))
slopes[:, 2:] *= 2
slopes = np.kron(slopes, np.ones((4, 1))) * ex_vc
errors += slopes.sum(1)
errors += np.random.normal(size=n)
endog = exog.sum(1) + errors
exog_vc = {"a": {}, "b": {}}
for k, group in enumerate(range(int(n / 4))):
ix = np.flatnonzero(groups == group)
exog_vc["a"][group] = ex_vc[ix, 0:2]
exog_vc["b"][group] = ex_vc[ix, 2:]
with pytest.warns(UserWarning, match="Using deprecated variance"):
model1 = MixedLM(endog, exog, groups, exog_re=exog_re,
exog_vc=exog_vc)
result1 = model1.fit()
df = pd.DataFrame(exog[:, 1:], columns=["x1"])
df["y"] = endog
df["re1"] = exog_re[:, 0]
df["re2"] = exog_re[:, 1]
df["vc1"] = ex_vc[:, 0]
df["vc2"] = ex_vc[:, 1]
df["vc3"] = ex_vc[:, 2]
df["vc4"] = ex_vc[:, 3]
vc_formula = {"a": "0 + vc1 + vc2", "b": "0 + vc3 + vc4"}
model2 = MixedLM.from_formula(
"y ~ x1",
groups=groups,
re_formula="0 + re1 + re2",
vc_formula=vc_formula,
data=df)
result2 = model2.fit()
assert_allclose(result1.fe_params, result2.fe_params, rtol=1e-8)
assert_allclose(result1.cov_re, result2.cov_re, rtol=1e-8)
assert_allclose(result1.vcomp, result2.vcomp, rtol=1e-8)
assert_allclose(result1.params, result2.params, rtol=1e-8)
assert_allclose(result1.bse, result2.bse, rtol=1e-8)
def test_formulas(self):
np.random.seed(2410)
exog = np.random.normal(size=(300, 4))
exog_re = np.random.normal(size=300)
groups = np.kron(np.arange(100), [1, 1, 1])
g_errors = exog_re * np.kron(np.random.normal(size=100), [1, 1, 1])
endog = exog.sum(1) + g_errors + np.random.normal(size=300)
mod1 = MixedLM(endog, exog, groups, exog_re)
# test the names
assert_(mod1.data.xnames == ["x1", "x2", "x3", "x4"])
assert_(mod1.data.exog_re_names == ["x_re1"])
assert_(mod1.data.exog_re_names_full == ["x_re1 Var"])
rslt1 = mod1.fit()
# Fit with a formula, passing groups as the actual values.
df = pd.DataFrame({"endog": endog})
for k in range(exog.shape[1]):
df["exog%d" % k] = exog[:, k]
df["exog_re"] = exog_re
fml = "endog ~ 0 + exog0 + exog1 + exog2 + exog3"
re_fml = "0 + exog_re"
mod2 = MixedLM.from_formula(fml, df, re_formula=re_fml, groups=groups)
assert_(mod2.data.xnames == ["exog0", "exog1", "exog2", "exog3"])
assert_(mod2.data.exog_re_names == ["exog_re"])
assert_(mod2.data.exog_re_names_full == ["exog_re Var"])
rslt2 = mod2.fit()
assert_almost_equal(rslt1.params, rslt2.params)
# Fit with a formula, passing groups as the variable name.
df["groups"] = groups
mod3 = MixedLM.from_formula(
fml, df, re_formula=re_fml, groups="groups")
assert_(mod3.data.xnames == ["exog0", "exog1", "exog2", "exog3"])
assert_(mod3.data.exog_re_names == ["exog_re"])
assert_(mod3.data.exog_re_names_full == ["exog_re Var"])
rslt3 = mod3.fit(start_params=rslt2.params)
assert_allclose(rslt1.params, rslt3.params, rtol=1e-4)
# Check default variance structure with non-formula model
# creation, also use different exog_re that produces a zero
# estimated variance parameter.
exog_re = np.ones(len(endog), dtype=np.float64)
mod4 = MixedLM(endog, exog, groups, exog_re)
with warnings.catch_warnings():
warnings.simplefilter("ignore")
rslt4 = mod4.fit()
from statsmodels.formula.api import mixedlm
mod5 = mixedlm(fml, df, groups="groups")
assert_(mod5.data.exog_re_names == ["groups"])
assert_(mod5.data.exog_re_names_full == ["groups Var"])
with warnings.catch_warnings():
warnings.simplefilter("ignore")
rslt5 = mod5.fit()
assert_almost_equal(rslt4.params, rslt5.params)
@pytest.mark.slow
def test_regularized(self):
np.random.seed(3453)
exog = np.random.normal(size=(400, 5))
groups = np.kron(np.arange(100), np.ones(4))
expected_endog = exog[:, 0] - exog[:, 2]
endog = expected_endog +\
np.kron(np.random.normal(size=100), np.ones(4)) +\
np.random.normal(size=400)
# L1 regularization
md = MixedLM(endog, exog, groups)
mdf1 = md.fit_regularized(alpha=1.)
mdf1.summary()
# L1 regularization
md = MixedLM(endog, exog, groups)
mdf2 = md.fit_regularized(alpha=10 * np.ones(5))
mdf2.summary()
# L2 regularization
pen = penalties.L2()
mdf3 = md.fit_regularized(method=pen, alpha=0.)
mdf3.summary()
# L2 regularization
pen = penalties.L2()
with warnings.catch_warnings():
warnings.simplefilter("ignore")
mdf4 = md.fit_regularized(method=pen, alpha=10.)
mdf4.summary()
# Pseudo-Huber regularization
pen = penalties.PseudoHuber(0.3)
mdf5 = md.fit_regularized(method=pen, alpha=1.)
mdf5.summary()
# ------------------------------------------------------------------
class TestMixedLMSummary:
# Test various aspects of the MixedLM summary
@classmethod
def setup_class(cls):
# Setup the model and estimate it.
pid = np.repeat([0, 1], 5)
x0 = np.repeat([1], 10)
x1 = [1, 5, 7, 3, 5, 1, 2, 6, 9, 8]
x2 = [6, 2, 1, 0, 1, 4, 3, 8, 2, 1]
y = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
df = pd.DataFrame({"y": y, "pid": pid, "x0": x0, "x1": x1, "x2": x2})
endog = df["y"].values
exog = df[["x0", "x1", "x2"]].values
groups = df["pid"].values
cls.res = MixedLM(endog, exog, groups=groups).fit()
def test_summary(self):
# Test that the summary correctly includes all variables.
summ = self.res.summary()
desired = ["const", "x1", "x2", "Group Var"]
# Second table is summary of params
actual = summ.tables[1].index.values
assert_equal(actual, desired)
def test_summary_xname_fe(self):
# Test that the `xname_fe` argument is reflected in the summary table.
summ = self.res.summary(xname_fe=["Constant", "Age", "Weight"])
desired = ["Constant", "Age", "Weight", "Group Var"]
actual = summ.tables[
1].index.values # Second table is summary of params
assert_equal(actual, desired)
def test_summary_xname_re(self):
# Test that the `xname_re` argument is reflected in the summary table.
summ = self.res.summary(xname_re=["Random Effects"])
desired = ["const", "x1", "x2", "Random Effects"]
actual = summ.tables[
1].index.values # Second table is summary of params
assert_equal(actual, desired)
# ------------------------------------------------------------------
class TestMixedLMSummaryRegularized(TestMixedLMSummary):
# Test various aspects of the MixedLM summary
# after fitting model with fit_regularized function
@classmethod
def setup_class(cls):
# Setup the model and estimate it.
pid = np.repeat([0, 1], 5)
x0 = np.repeat([1], 10)
x1 = [1, 5, 7, 3, 5, 1, 2, 6, 9, 8]
x2 = [6, 2, 1, 0, 1, 4, 3, 8, 2, 1]
y = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
df = pd.DataFrame({"y": y, "pid": pid, "x0": x0, "x1": x1, "x2": x2})
endog = df["y"].values
exog = df[["x0", "x1", "x2"]].values
groups = df["pid"].values
cls.res = MixedLM(endog, exog, groups=groups).fit_regularized()
# ------------------------------------------------------------------
# TODO: better name
def do1(reml, irf, ds_ix):
# No need to check independent random effects when there is
# only one of them.
if irf and ds_ix < 6:
return
irfs = "irf" if irf else "drf"
meth = "reml" if reml else "ml"
rslt = R_Results(meth, irfs, ds_ix)
# Fit the model
md = MixedLM(rslt.endog, rslt.exog_fe, rslt.groups, rslt.exog_re)
if not irf: # Free random effects covariance
if np.any(np.diag(rslt.cov_re_r) < 1e-5):
with warnings.catch_warnings():
warnings.simplefilter("ignore")
mdf = md.fit(gtol=1e-7, reml=reml)
else:
mdf = md.fit(gtol=1e-7, reml=reml)
else: # Independent random effects
k_fe = rslt.exog_fe.shape[1]
k_re = rslt.exog_re.shape[1]
free = MixedLMParams(k_fe, k_re, 0)
free.fe_params = np.ones(k_fe)
free.cov_re = np.eye(k_re)
free.vcomp = np.array([])
if np.any(np.diag(rslt.cov_re_r) < 1e-5):
with warnings.catch_warnings():
warnings.simplefilter("ignore")
mdf = md.fit(reml=reml, gtol=1e-7, free=free)
else:
mdf = md.fit(reml=reml, gtol=1e-7, free=free)
assert_almost_equal(mdf.fe_params, rslt.coef, decimal=4)
assert_almost_equal(mdf.cov_re, rslt.cov_re_r, decimal=4)
assert_almost_equal(mdf.scale, rslt.scale_r, decimal=4)
k_fe = md.k_fe
assert_almost_equal(
rslt.vcov_r, mdf.cov_params()[0:k_fe, 0:k_fe], decimal=3)
assert_almost_equal(mdf.llf, rslt.loglike[0], decimal=2)
# Not supported in R except for independent random effects
if not irf:
assert_almost_equal(
mdf.random_effects[0], rslt.ranef_postmean, decimal=3)
assert_almost_equal(
mdf.random_effects_cov[0], rslt.ranef_condvar, decimal=3)
# ------------------------------------------------------------------
# Run all the tests against R
cur_dir = os.path.dirname(os.path.abspath(__file__))
rdir = os.path.join(cur_dir, 'results')
fnames = os.listdir(rdir)
fnames = [x for x in fnames if x.startswith("lme") and x.endswith(".csv")]
# Copied from #3847
@pytest.mark.parametrize('fname', fnames)
@pytest.mark.parametrize('reml', [False, True])
@pytest.mark.parametrize('irf', [False, True])
def test_r(fname, reml, irf):
ds_ix = int(fname[3:5])
do1(reml, irf, ds_ix)
# ------------------------------------------------------------------
def test_mixed_lm_wrapper():
# a bit more complicated model to test
np.random.seed(2410)
exog = np.random.normal(size=(300, 4))
exog_re = np.random.normal(size=300)
groups = np.kron(np.arange(100), [1, 1, 1])
g_errors = exog_re * np.kron(np.random.normal(size=100), [1, 1, 1])
endog = exog.sum(1) + g_errors + np.random.normal(size=300)
# Fit with a formula, passing groups as the actual values.
df = pd.DataFrame({"endog": endog})
for k in range(exog.shape[1]):
df["exog%d" % k] = exog[:, k]
df["exog_re"] = exog_re
fml = "endog ~ 0 + exog0 + exog1 + exog2 + exog3"
re_fml = "~ exog_re"
mod2 = MixedLM.from_formula(fml, df, re_formula=re_fml, groups=groups)
result = mod2.fit()
result.summary()
xnames = ["exog0", "exog1", "exog2", "exog3"]
re_names = ["Group", "exog_re"]
re_names_full = ["Group Var", "Group x exog_re Cov", "exog_re Var"]
assert_(mod2.data.xnames == xnames)
assert_(mod2.data.exog_re_names == re_names)
assert_(mod2.data.exog_re_names_full == re_names_full)
params = result.params
assert_(params.index.tolist() == xnames + re_names_full)
bse = result.bse
assert_(bse.index.tolist() == xnames + re_names_full)
tvalues = result.tvalues
assert_(tvalues.index.tolist() == xnames + re_names_full)
cov_params = result.cov_params()
assert_(cov_params.index.tolist() == xnames + re_names_full)
assert_(cov_params.columns.tolist() == xnames + re_names_full)
fe = result.fe_params
assert_(fe.index.tolist() == xnames)
bse_fe = result.bse_fe
assert_(bse_fe.index.tolist() == xnames)
cov_re = result.cov_re
assert_(cov_re.index.tolist() == re_names)
assert_(cov_re.columns.tolist() == re_names)
cov_re_u = result.cov_re_unscaled
assert_(cov_re_u.index.tolist() == re_names)
assert_(cov_re_u.columns.tolist() == re_names)
bse_re = result.bse_re
assert_(bse_re.index.tolist() == re_names_full)
def test_random_effects():
np.random.seed(23429)
# Default model (random effects only)
ngrp = 100
gsize = 10
rsd = 2
gsd = 3
mn = gsd * np.random.normal(size=ngrp)
gmn = np.kron(mn, np.ones(gsize))
y = gmn + rsd * np.random.normal(size=ngrp * gsize)
gr = np.kron(np.arange(ngrp), np.ones(gsize))
x = np.ones(ngrp * gsize)
model = MixedLM(y, x, groups=gr)
result = model.fit()
re = result.random_effects
assert_(isinstance(re, dict))
assert_(len(re) == ngrp)
assert_(isinstance(re[0], pd.Series))
assert_(len(re[0]) == 1)
# Random intercept only, set explicitly
model = MixedLM(y, x, exog_re=x, groups=gr)
result = model.fit()
re = result.random_effects
assert_(isinstance(re, dict))
assert_(len(re) == ngrp)
assert_(isinstance(re[0], pd.Series))
assert_(len(re[0]) == 1)
# Random intercept and slope
xr = np.random.normal(size=(ngrp * gsize, 2))
xr[:, 0] = 1
qp = np.linspace(-1, 1, gsize)
xr[:, 1] = np.kron(np.ones(ngrp), qp)
model = MixedLM(y, x, exog_re=xr, groups=gr)
result = model.fit()
re = result.random_effects
assert_(isinstance(re, dict))
assert_(len(re) == ngrp)
assert_(isinstance(re[0], pd.Series))
assert_(len(re[0]) == 2)
@pytest.mark.slow
def test_handle_missing():
np.random.seed(23423)
df = np.random.normal(size=(100, 6))
df = pd.DataFrame(df)
df.columns = ["y", "g", "x1", "z1", "c1", "c2"]
df["g"] = np.kron(np.arange(50), np.ones(2))
re = np.random.normal(size=(50, 4))
re = np.kron(re, np.ones((2, 1)))
df["y"] = re[:, 0] + re[:, 1] * df.z1 + re[:, 2] * df.c1
df["y"] += re[:, 3] * df.c2 + np.random.normal(size=100)
df.loc[1, "y"] = np.nan
df.loc[2, "g"] = np.nan
df.loc[3, "x1"] = np.nan
df.loc[4, "z1"] = np.nan
df.loc[5, "c1"] = np.nan
df.loc[6, "c2"] = np.nan
fml = "y ~ x1"
re_formula = "1 + z1"
vc_formula = {"a": "0 + c1", "b": "0 + c2"}
for include_re in False, True:
for include_vc in False, True:
kwargs = {}
dx = df.copy()
va = ["y", "g", "x1"]
if include_re:
kwargs["re_formula"] = re_formula
va.append("z1")
if include_vc:
kwargs["vc_formula"] = vc_formula
va.extend(["c1", "c2"])
dx = dx[va].dropna()
# Some of these models are severely misspecified with
# small n, so produce convergence warnings. Not relevant
# to what we are checking here.
with warnings.catch_warnings():
warnings.simplefilter("ignore")
# Drop missing externally
model1 = MixedLM.from_formula(
fml, groups="g", data=dx, **kwargs)
result1 = model1.fit()
# MixeLM handles missing
model2 = MixedLM.from_formula(
fml, groups="g", data=df, missing='drop', **kwargs)
result2 = model2.fit()
assert_allclose(result1.params, result2.params)
assert_allclose(result1.bse, result2.bse)
assert_equal(len(result1.fittedvalues), result1.nobs)
def test_summary_col():
from statsmodels.iolib.summary2 import summary_col
ids = [1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3]
x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
# hard coded simulated y
# ids = np.asarray(ids)
# np.random.seed(123987)
# y = x + np.array([-1, 0, 1])[ids - 1] + 2 * np.random.randn(len(y))
y = np.array([
1.727, -1.037, 2.904, 3.569, 4.629, 5.736, 6.747, 7.020, 5.624, 10.155,
10.400, 17.164, 17.276, 14.988, 14.453
])
d = {'Y': y, 'X': x, 'IDS': ids}
d = pd.DataFrame(d)
# provide start_params to speed up convergence
sp1 = np.array([-1.26722599, 1.1617587, 0.19547518])
mod1 = MixedLM.from_formula('Y ~ X', d, groups=d['IDS'])
results1 = mod1.fit(start_params=sp1)
sp2 = np.array([3.48416861, 0.55287862, 1.38537901])
mod2 = MixedLM.from_formula('X ~ Y', d, groups=d['IDS'])
results2 = mod2.fit(start_params=sp2)
out = summary_col(
[results1, results2],
stars=True,
regressor_order=["Group Var", "Intercept", "X", "Y"]
)
s = ('\n=============================\n Y X \n'
'-----------------------------\nGroup Var 0.1955 1.3854 \n'
' (0.6032) (2.7377) \nIntercept -1.2672 3.4842* \n'
' (1.6546) (1.8882) \nX 1.1618*** \n'
' (0.1959) \nY 0.5529***\n'
' (0.2080) \n=============================\n'
'Standard errors in\nparentheses.\n* p<.1, ** p<.05, ***p<.01')
assert_equal(str(out), s)
@pytest.mark.slow
def test_random_effects_getters():
# Simulation-based test to make sure that the BLUPs and actual
# random effects line up.
np.random.seed(34234)
ng = 500 # number of groups
m = 10 # group size
y, x, z, v0, v1, g, b, c0, c1 = [], [], [], [], [], [], [], [], []
for i in range(ng):
# Fixed effects
xx = np.random.normal(size=(m, 2))
yy = xx[:, 0] + 0.5 * np.random.normal(size=m)
# Random effects (re_formula)
zz = np.random.normal(size=(m, 2))
bb = np.random.normal(size=2)
bb[0] *= 3
bb[1] *= 1
yy += np.dot(zz, bb).flat
b.append(bb)
# First variance component
vv0 = np.kron(np.r_[0, 1], np.ones(m // 2)).astype(int)
cc0 = np.random.normal(size=2)
yy += cc0[vv0]
v0.append(vv0)
c0.append(cc0)
# Second variance component
vv1 = np.kron(np.ones(m // 2), np.r_[0, 1]).astype(int)
cc1 = np.random.normal(size=2)
yy += cc1[vv1]
v1.append(vv1)
c1.append(cc1)
y.append(yy)
x.append(xx)
z.append(zz)
g.append(["g%d" % i] * m)
y = np.concatenate(y)
x = np.concatenate(x)
z = np.concatenate(z)
v0 = np.concatenate(v0)
v1 = np.concatenate(v1)
g = np.concatenate(g)
df = pd.DataFrame({
"y": y,
"x0": x[:, 0],
"x1": x[:, 1],
"z0": z[:, 0],
"z1": z[:, 1],
"v0": v0,
"v1": v1,
"g": g
})
b = np.asarray(b)
c0 = np.asarray(c0)
c1 = np.asarray(c1)
cc = np.concatenate((c0, c1), axis=1)
model = MixedLM.from_formula(
"y ~ x0 + x1",
re_formula="~0 + z0 + z1",
vc_formula={
"v0": "~0+C(v0)",
"v1": "0+C(v1)"
},
groups="g",
data=df)
result = model.fit()
ref = result.random_effects
b0 = [ref["g%d" % k][0:2] for k in range(ng)]
b0 = np.asarray(b0)
assert (np.corrcoef(b0[:, 0], b[:, 0])[0, 1] > 0.8)
assert (np.corrcoef(b0[:, 1], b[:, 1])[0, 1] > 0.8)
cf0 = [ref["g%d" % k][2:6] for k in range(ng)]
cf0 = np.asarray(cf0)
for k in range(4):
assert (np.corrcoef(cf0[:, k], cc[:, k])[0, 1] > 0.8)
# Smoke test for predictive covariances
refc = result.random_effects_cov
for g in refc.keys():
p = ref[g].size
assert (refc[g].shape == (p, p))
def check_smw_solver(p, q, r, s):
# Helper to check that _smw_solver results do in fact solve the desired
# SMW equation
d = q - r
A = np.random.normal(size=(p, q))
AtA = np.dot(A.T, A)
B = np.zeros((q, q))
B[0:r, 0:r] = np.random.normal(size=(r, r))
di = np.random.uniform(size=d)
B[r:q, r:q] = np.diag(1 / di)
Qi = np.linalg.inv(B[0:r, 0:r])
s = 0.5
x = np.random.normal(size=p)
y2 = np.linalg.solve(s * np.eye(p, p) + np.dot(A, np.dot(B, A.T)), x)
f = _smw_solver(s, A, AtA, Qi, di)
y1 = f(x)
assert_allclose(y1, y2)
f = _smw_solver(s, sparse.csr_matrix(A), sparse.csr_matrix(AtA), Qi,
di)
y1 = f(x)
assert_allclose(y1, y2)
class TestSMWSolver:
@classmethod
def setup_class(cls):
np.random.seed(23)
@pytest.mark.parametrize("p", [5, 10])
@pytest.mark.parametrize("q", [4, 8])
@pytest.mark.parametrize("r", [2, 3])
@pytest.mark.parametrize("s", [0, 0.5])
def test_smw_solver(self, p, q, r, s):
check_smw_solver(p, q, r, s)
def check_smw_logdet(p, q, r, s):
# Helper to check that _smw_logdet results match non-optimized equivalent
d = q - r
A = np.random.normal(size=(p, q))
AtA = np.dot(A.T, A)
B = np.zeros((q, q))
c = np.random.normal(size=(r, r))
B[0:r, 0:r] = np.dot(c.T, c)
di = np.random.uniform(size=d)
B[r:q, r:q] = np.diag(1 / di)
Qi = np.linalg.inv(B[0:r, 0:r])
s = 0.5
_, d2 = np.linalg.slogdet(s * np.eye(p, p) + np.dot(A, np.dot(B, A.T)))
_, bd = np.linalg.slogdet(B)
d1 = _smw_logdet(s, A, AtA, Qi, di, bd)
# GH 5642, OSX OpenBlas tolerance increase
rtol = 1e-6 if PLATFORM_OSX else 1e-7
assert_allclose(d1, d2, rtol=rtol)
class TestSMWLogdet:
@classmethod
def setup_class(cls):
np.random.seed(23)
@pytest.mark.parametrize("p", [5, 10])
@pytest.mark.parametrize("q", [4, 8])
@pytest.mark.parametrize("r", [2, 3])
@pytest.mark.parametrize("s", [0, 0.5])
def test_smw_logdet(self, p, q, r, s):
check_smw_logdet(p, q, r, s)
def test_singular():
# Issue #7051
np.random.seed(3423)
n = 100
data = np.random.randn(n, 2)
df = pd.DataFrame(data, columns=['Y', 'X'])
df['class'] = pd.Series([i % 3 for i in df.index], index=df.index)
with pytest.warns(Warning) as wrn:
md = MixedLM.from_formula("Y ~ X", df, groups=df['class'])
mdf = md.fit()
mdf.summary()
if not wrn:
pytest.fail("warning expected")
def test_get_distribution():
np.random.seed(234)
n = 100
n_groups = 10
fe_params = np.r_[1, -2]
cov_re = np.asarray([[1, 0.5], [0.5, 2]])
vcomp = np.r_[0.5**2, 1.5**2]
scale = 1.5
exog_fe = np.random.normal(size=(n, 2))
exog_re = np.random.normal(size=(n, 2))
exog_vca = np.random.normal(size=(n, 2))
exog_vcb = np.random.normal(size=(n, 2))
groups = np.repeat(np.arange(n_groups, dtype=int),
n / n_groups)
ey = np.dot(exog_fe, fe_params)
u = np.random.normal(size=(n_groups, 2))
u = np.dot(u, np.linalg.cholesky(cov_re).T)
u1 = np.sqrt(vcomp[0]) * np.random.normal(size=(n_groups, 2))
u2 = np.sqrt(vcomp[1]) * np.random.normal(size=(n_groups, 2))
y = ey + (u[groups, :] * exog_re).sum(1)
y += (u1[groups, :] * exog_vca).sum(1)
y += (u2[groups, :] * exog_vcb).sum(1)
y += np.sqrt(scale) * np.random.normal(size=n)
df = pd.DataFrame({"y": y, "x1": exog_fe[:, 0], "x2": exog_fe[:, 1],
"z0": exog_re[:, 0], "z1": exog_re[:, 1],
"grp": groups})
df["z2"] = exog_vca[:, 0]
df["z3"] = exog_vca[:, 1]
df["z4"] = exog_vcb[:, 0]
df["z5"] = exog_vcb[:, 1]
vcf = {"a": "0 + z2 + z3", "b": "0 + z4 + z5"}
m = MixedLM.from_formula("y ~ 0 + x1 + x2", groups="grp",
re_formula="0 + z0 + z1",
vc_formula=vcf, data=df)
# Build a params vector that is comparable to
# MixedLMResults.params
import statsmodels
mp = statsmodels.regression.mixed_linear_model.MixedLMParams
po = mp.from_components(fe_params=fe_params, cov_re=cov_re,
vcomp=vcomp)
pa = po.get_packed(has_fe=True, use_sqrt=False)
pa[len(fe_params):] /= scale
# Get a realization
dist = m.get_distribution(pa, scale, None)
yr = dist.rvs(0)
# Check the overall variance
v = (np.dot(exog_re, cov_re) * exog_re).sum(1).mean()
v += vcomp[0] * (exog_vca**2).sum(1).mean()
v += vcomp[1] * (exog_vcb**2).sum(1).mean()
v += scale
assert_allclose(np.var(yr - ey), v, rtol=1e-2, atol=1e-4)