def compute_ci(data,
outcome,
estimates,
ci_method="percentile",
alpha=0.05,
n_cores=1):
"""Compute confidence interval of bootstrap estimates. Parts of the code of the
subfunctions of this function are taken from Daniel Saxton's resample library, as
found on https://github.com/dsaxton/resample/ .
Args:
data (pandas.DataFrame): original dataset.
outcome (callable): function of the data calculating statistic of interest.
Needs to return a pandas Series.
estimates (pandas.DataFrame): DataFrame of estimates in the bootstrap samples.
ci_method (str): method of choice for confidence interval computation.
alpha (float): significance level of choice.
n_cores (int): number of jobs for parallelization.
Returns:
cis (pandas.DataFrame): DataFrame where k'th row contains CI for k'th parameter.
"""
check_inputs(data=data, alpha=alpha, ci_method=ci_method)
funcname = "_ci_" + ci_method
cis = globals()[funcname](data, outcome, estimates, alpha, n_cores)
return pd.DataFrame(cis,
index=estimates.columns.tolist(),
columns=["lower_ci", "upper_ci"])
def test_check_inputs_cluster_by(setup):
cluster_by = "this is not a column name of df"
expected_msg = "Input 'cluster_by' must be None or a column name of 'data'."
with pytest.raises(ValueError) as error:
check_inputs(data=setup["df"], cluster_by=cluster_by)
assert str(error.value) == expected_msg
def test_check_inputs_data():
data = "this is not a data frame"
expected_msg = "Data must be a pandas.DataFrame or pandas.Series."
with pytest.raises(TypeError) as error:
check_inputs(data=data)
assert str(error.value) == expected_msg
def test_check_inputs_ci_level(setup):
ci_level = 666
expected_msg = "Input 'ci_level' must be in [0,1]."
with pytest.raises(ValueError) as error:
check_inputs(data=setup["df"], ci_level=ci_level)
assert str(error.value) == expected_msg
def test_check_inputs_ci_method(setup, expected):
ci_method = 4
with pytest.raises(ValueError) as excinfo:
check_inputs(data=setup["df"], ci_method=ci_method)
expected_msg = ("ci_method must be 'percentile', 'bc',"
f" 'bca', 't', 'basic' or 'normal', '{ci_method}'"
f" was supplied")
assert str(excinfo.value) == expected_msg
def get_bootstrap_outcomes(
data,
outcome,
outcome_kwargs=None,
cluster_by=None,
seed=None,
n_draws=1000,
n_cores=1,
error_handling="continue",
batch_evaluator=joblib_batch_evaluator,
):
"""Draw bootstrap samples and calculate outcomes.
Args:
data (pandas.DataFrame): original dataset.
outcome (callable): function of the dataset calculating statistic of interest.
Needs to return array-like object or pd.Series.
cluster_by (str): column name of the variable to cluster by.
seed (int): Random seed.
n_draws (int): number of draws, only relevant if seeds is None.
n_cores (int): number of jobs for parallelization.
error_handling (str): One of "continue", "raise". Default "continue" which means
that bootstrap estimates are only calculated for those samples where no
errors occur and a warning is produced if any error occurs.
batch_evaluator (str or Callable): Name of a pre-implemented batch evaluator
(currently 'joblib' and 'pathos_mp') or Callable with the same interface
as the estimagic batch_evaluators. See :ref:`batch_evaluators`.
Returns:
estimates (pandas.DataFrame): Outcomes for different bootstrap samples. The
columns are the index of the result of ``outcome``.
"""
check_inputs(data=data, cluster_by=cluster_by)
if outcome_kwargs is not None:
outcome = partial(outcome, *outcome_kwargs)
indices = get_bootstrap_indices(
data=data,
cluster_by=cluster_by,
seed=seed,
n_draws=n_draws,
)
estimates = _get_bootstrap_outcomes_from_indices(
indices=indices,
data=data,
outcome=outcome,
n_cores=n_cores,
error_handling=error_handling,
batch_evaluator=batch_evaluator,
)
return estimates
def get_bootstrap_outcomes(
data,
outcome,
cluster_by=None,
rng=None,
n_draws=1000,
n_cores=1,
error_handling="continue",
batch_evaluator="joblib",
):
"""Draw bootstrap samples and calculate outcomes.
Args:
data (pandas.DataFrame): original dataset.
outcome (callable): function of the dataset calculating statistic of interest.
Returns a general pytree (e.g. pandas Series, dict, numpy array, etc.).
cluster_by (str): column name of the variable to cluster by.
rng (numpy.random.Generator): A random number generator.
n_draws (int): number of bootstrap draws.
n_cores (int): number of jobs for parallelization.
error_handling (str): One of "continue", "raise". Default "continue" which means
that bootstrap estimates are only calculated for those samples where no
errors occur and a warning is produced if any error occurs.
batch_evaluator (str or Callable): Name of a pre-implemented batch evaluator
(currently 'joblib' and 'pathos_mp') or Callable with the same interface
as the estimagic batch_evaluators. See :ref:`batch_evaluators`.
Returns:
estimates (list): List of pytrees of estimated bootstrap outcomes.
"""
check_inputs(data=data, cluster_by=cluster_by)
batch_evaluator = process_batch_evaluator(batch_evaluator)
indices = get_bootstrap_indices(
data=data,
rng=rng,
cluster_by=cluster_by,
n_draws=n_draws,
)
estimates = _get_bootstrap_outcomes_from_indices(
indices=indices,
data=data,
outcome=outcome,
n_cores=n_cores,
error_handling=error_handling,
batch_evaluator=batch_evaluator,
)
return estimates
def calculate_ci(
base_outcome,
estimates,
ci_method="percentile",
ci_level=0.95,
):
"""Compute confidence interval of bootstrap estimates.
Parts of the code of the subfunctions of this function are taken from
Daniel Saxton's resample library, as found on
https://github.com/dsaxton/resample/
Args:
base_outcome (list): List of flat base outcomes, i.e. the outcome
statistic(s) evaluated on the original data set.
estimates (np.ndarray): Array of estimates computed on the bootstrapped
samples.
ci_method (str): Method of choice for computing confidence intervals.
The default is "percentile".
ci_level (float): Confidence level for the calculation of confidence
intervals. The default is 0.95.
Returns:
np.ndarray: 1d array of the lower confidence interval, where the k'th entry
contains the lower confidence interval for the k'th parameter.
np.ndarray: 1d array of the upper confidence interval, where the k'th entry
contains the upper confidence interval for the k'th parameter.
"""
check_inputs(ci_method=ci_method, ci_level=ci_level, skipdata=True)
alpha = 1 - ci_level
if ci_method == "percentile":
cis = _ci_percentile(estimates, alpha)
elif ci_method == "bc":
cis = _ci_bc(estimates, base_outcome, alpha)
elif ci_method == "t":
cis = _ci_t(estimates, base_outcome, alpha)
elif ci_method == "basic":
cis = _ci_basic(estimates, base_outcome, alpha)
elif ci_method == "normal":
cis = _ci_normal(estimates, base_outcome, alpha)
return cis[:, 0], cis[:, 1]
def bootstrap_from_outcomes(
data, outcome, bootstrap_outcomes, ci_method="percentile", alpha=0.05, n_cores=1
):
"""Set up results table containing mean, standard deviation and confidence interval
for each estimated parameter.
Args:
data (pandas.DataFrame): original dataset.
outcome (callable): function of the data calculating statistic of interest.
Needs to return a pandas Series.
bootstrap_outcomes (pandas.DataFrame): DataFrame of bootstrap_outcomes in the
bootstrap samples.
ci_method (str): method of choice for confidence interval computation.
n_cores (int): number of jobs for parallelization.
alpha (float): significance level of choice.
Returns:
results (pandas.DataFrame): table of results.
"""
check_inputs(data=data, ci_method=ci_method, alpha=alpha)
summary = pd.DataFrame(bootstrap_outcomes.mean(axis=0), columns=["mean"])
summary["std"] = bootstrap_outcomes.std(axis=0)
cis = compute_ci(data, outcome, bootstrap_outcomes, ci_method, alpha, n_cores)
summary["lower_ci"] = cis["lower_ci"]
summary["upper_ci"] = cis["upper_ci"]
cov = bootstrap_outcomes.cov()
out = {"summary": summary, "cov": cov, "outcomes": bootstrap_outcomes}
return out
seeds (numpy.array): array of seeds for bootstrap samples, default is none.
n_cores (int): number of jobs for parallelization.
error_handling (str): One of "continue", "raise". Default "continue" which means
that bootstrap estimates are only calculated for those samples where no
errors occur and a warning is produced if any error occurs.
batch_evaluator (str or Callable): Name of a pre-implemented batch evaluator
(currently 'joblib' and 'pathos_mp') or Callable with the same interface
as the estimagic batch_evaluators. See :ref:`batch_evaluators`.
Returns:
results (pandas.DataFrame): DataFrame where k'th row contains mean estimate,
standard error, and confidence interval of k'th parameter.
"""
check_inputs(data, cluster_by, ci_method, alpha)
estimates = get_bootstrap_outcomes(
data=data,
outcome=outcome,
outcome_kwargs=outcome_kwargs,
cluster_by=cluster_by,
seed=seed,
n_draws=n_draws,
n_cores=n_cores,
error_handling=error_handling,
batch_evaluator=batch_evaluator,
)
out = bootstrap_from_outcomes(data, outcome, estimates, ci_method, alpha, n_cores)
def test_check_inputs_alpha(setup, expected):
alpha = 666
with pytest.raises(ValueError) as excinfo:
check_inputs(data=setup["df"], alpha=alpha)
assert "Input 'alpha' must be in [0,1]." == str(excinfo.value)
def test_check_inputs_cluster_by(setup, expected):
cluster_by = "this is not a column name of df"
with pytest.raises(ValueError) as excinfo:
check_inputs(data=setup["df"], cluster_by=cluster_by)
assert "Input 'cluster_by' must be None or a column name of DataFrame." == str(
excinfo.value)
def test_check_inputs_data(setup, expected):
data = "this is not a data frame"
with pytest.raises(ValueError) as excinfo:
check_inputs(data=data)
assert "Input 'data' must be DataFrame." == str(excinfo.value)
Generator instance then that instance is used.
n_cores (int): number of jobs for parallelization.
error_handling (str): One of "continue", "raise". Default "continue" which means
that bootstrap estimates are only calculated for those samples where no
errors occur and a warning is produced if any error occurs.
batch_evaluator (str or Callable): Name of a pre-implemented batch evaluator
(currently 'joblib' and 'pathos_mp') or Callable with the same interface
as the estimagic batch_evaluators. See :ref:`batch_evaluators`.
Returns:
BootstrapResult: A BootstrapResult object storing information on summary
statistics, the covariance matrix, and estimated boostrap outcomes.
"""
if callable(outcome):
check_inputs(data=data, cluster_by=cluster_by)
if outcome_kwargs is not None:
outcome = functools.partial(outcome, **outcome_kwargs)
else:
raise ValueError("outcome must be a callable.")
if existing_result is None:
base_outcome = outcome(data)
existing_outcomes = []
elif isinstance(existing_result, BootstrapResult):
base_outcome = existing_result.base_outcome
existing_outcomes = existing_result.outcomes
else:
raise ValueError("existing_result must be None or a BootstrapResult.")
