Source code for andrey.api.hybrid

"""Hybrid facade adapters: a restrict phase of conditional-independence tests, then a score search.

``mmhc`` and ``rsmax2`` share :mod:`andrey.search.hybrid`: the restrict phase learns the candidate
pairs and the maximize phase runs :func:`andrey.hc` or :func:`andrey.tabu` among them.
"""

from __future__ import annotations

from typing import TYPE_CHECKING

from andrey.api._adapt import (
    categorical_metadata,
    checked_data,
    column_labels,
    copies_named,
    data_kind,
    default_score,
    default_test,
    int_in_range,
    json_safe,
    structure_output,
)
from andrey.api._method import method_spec
from andrey.core.knowledge import Knowledge, resolve

if TYPE_CHECKING:
    from collections.abc import Sequence

    import numpy.typing as npt

    from andrey.core import StructureOutput


def _fit(
    name: str,
    data: npt.ArrayLike,
    *,
    restrict: str,
    maximize: str,
    alpha: float,
    indep_test: str | None,
    score_func: str | None,
    penalty_discount: float,
    ebic_gamma: float,
    equivalent_sample_size: float,
    max_iter: int | None,
    tabu_length: int,
    max_tabu: int | None,
    categorical: Sequence[str | int] | None,
    seed: int | None,
    max_depth: int | None,
    max_parents: int | None,
    knowledge: Knowledge | None,
) -> StructureOutput:
    """Check the settings, run the restrict and maximize phases, and wrap the CPDAG."""
    from andrey.search.hybrid import rsmax2 as _rsmax2

    score_func, _ = default_score(data, score_func, categorical=categorical)
    indep_test, categorical = default_test(data, indep_test, categorical=categorical)
    # Both phases read the same data, so the score and the test must agree on its type.
    if data_kind(score_func) != data_kind(indep_test):
        raise ValueError(
            f"{name}'s score and test must read the data alike: score_func='bdeu' or "
            "'discrete_bic' with indep_test 'chisq' or 'gsq' for categories, "
            "'degen_gauss' or 'cond_gauss' with 'degen_gauss' or "
            "'cond_gauss' for mixed data, or 'bic' with a test of continuous "
            f"data; got score_func={score_func!r}, indep_test={indep_test!r}"
        )
    X, mask = checked_data(data, categorical, "indep_test", indep_test, method=name)
    max_tabu = int_in_range(
        tabu_length if max_tabu is None else max_tabu, "max_tabu", 1, tabu_length
    )
    labels = column_labels(data)
    constraints = resolve(knowledge, X.shape[1], labels, method=name)
    with copies_named(labels):
        cpdag, score, _ = _rsmax2(
            X,
            restrict=restrict,
            maximize=maximize,
            alpha=alpha,
            indep_test=indep_test,
            score_func=score_func,
            penalty_discount=penalty_discount,
            ebic_gamma=ebic_gamma,
            equivalent_sample_size=equivalent_sample_size,
            max_iter=max_iter,
            tabu_length=tabu_length,
            max_tabu=max_tabu,
            categorical=mask,
            constraints=constraints,
            seed=seed,
            max_depth=max_depth,
            max_parents=max_parents,
        )
    metadata = {
        "score": json_safe(score),
        **categorical_metadata(mask, data),
    }
    return structure_output(cpdag, labels=labels, metadata=metadata)


[docs] @method_spec("mmhc") def mmhc( data: npt.ArrayLike, *, alpha: float = 0.05, indep_test: str | None = None, score_func: str | None = None, penalty_discount: float = 1.0, ebic_gamma: float = 1.0, equivalent_sample_size: float = 1.0, max_iter: int | None = None, categorical: Sequence[str | int] | None = None, seed: int | None = None, max_depth: int | None = None, max_parents: int | None = None, knowledge: Knowledge | None = None, ) -> StructureOutput: """Learn a CPDAG from observational data with max-min hill climbing (MMHC). MMHC [1]_ first learns a skeleton with the max-min parents and children search (MMPC), which uses conditional-independence tests, then runs hill climbing over DAGs whose edges join only the pairs of that skeleton. It is :func:`~andrey.rsmax2` with ``restrict="mmpc"`` and ``maximize="hc"``. Parameters ---------- data : array-like of shape (n_samples, n_variables) Observed data, one row per sample. Coerced to ``float64``. A DataFrame's column names become the structure's ``labels``. alpha : float, default=0.05 Significance level of the conditional-independence test. Smaller values give sparser skeletons, so the score search considers fewer pairs. indep_test : str or None, default=None Conditional-independence test of the MMPC phase, any of :func:`~andrey.pc`'s: ``"fisherz"``, ``"student_t"``, or ``"normal_scores"`` for continuous data, ``"chisq"`` or ``"gsq"`` for categorical data, ``"degen_gauss"`` or ``"cond_gauss"`` for mixed data, or a nonlinear test. It must read the same kind of data as ``score_func``. ``None`` picks from the declared column types, as for :func:`~andrey.pc`. ``metadata["indep_test"]`` names the test the fit used: the one picked from the declared column types when this is ``None``. score_func : str or None, default=None Local score of the hill-climbing phase, any of :func:`~andrey.hc`'s: ``"bic"`` (Gaussian BIC) for continuous data, ``"bdeu"`` or ``"discrete_bic"`` for categorical data, ``"degen_gauss"`` or ``"cond_gauss"`` for mixed data. ``None`` picks from the declared column types, as for :func:`~andrey.ges`. ``metadata["score_func"]`` names the score the fit used: the one picked from the declared column types when this is ``None``. penalty_discount : float, default=1.0 Multiplier on the BIC penalty, as for :func:`~andrey.hc`. BDeu ignores it. ebic_gamma : float, default=1.0 Weight on the extended-BIC term of the linear-Gaussian BIC: each variable's score adds ``2 * ebic_gamma * log C(n_variables - 1, n_parents)``, which grows with the number of parent sets a variable can choose from. Larger values give sparser graphs; ``0.0`` is the standard BIC. Must be finite and non-negative. The other scores ignore it. See Notes. equivalent_sample_size : float, default=1.0 The equivalent sample size of the BDeu score: how many rows the uniform prior over each variable's conditional distributions is worth. A larger value weighs the prior more against the data, and the graph can change with it. Must be finite and positive. Only ``"bdeu"`` uses it: passing it with another score raises ``ValueError``. max_iter : int or None, default=None Maximum hill-climbing moves, at least ``1``; ``None`` sets no limit. categorical : sequence of str or int, optional The categorical columns of ``data``, for a mixed-data test and score, as for :func:`~andrey.pc`. A continuous setting raises ``ValueError`` on a declared column. seed : int or None, default=None ``None``, the default, is the configured seed, ``ANDREY_SEED`` or ``0`` when it is unset, not a fresh random one, so a fit repeats. Seed for the random draws of ``indep_test``, which only ``"rcot"``, ``"cmiknn"``, and ``"gpdc"`` make; the other tests ignore it. With those tests, ``metadata["seed"]`` records the seed used. max_depth : int or None, default=None The maximum conditioning-set size of every conditional-independence test in the MMPC phase, at least ``0``: ``0`` runs only unconditional tests, and ``None`` sets no limit. A smaller cap runs fewer tests and can keep pairs that a larger conditioning set would remove. max_parents : int or None, default=None A cap on every node's parents, at least ``0``: the score search takes no move that gives a node more than ``max_parents`` parents, so no DAG the returned CPDAG represents does (every DAG of a class has the same largest number of parents). A cap can stop the search short of the lowest-scoring graph. ``None`` sets no cap. knowledge : Knowledge or None, default=None Background knowledge, a :class:`~andrey.Knowledge`: required and forbidden edges, the pairs allowed to be adjacent, and temporal tiers, all honored. The score search considers the pairs of the MMPC skeleton and of the required edges, less the pairs the knowledge makes non-adjacent, and then honors the knowledge as :func:`~andrey.hc` does. The MMPC phase reads the data alone. Returns ------- StructureOutput Wraps a ``cpdag`` :class:`~andrey.core.GraphStructure`; ``metadata["algorithm"]`` is ``"mmhc"``, ``metadata["score"]`` the score of the DAG found, computed as for :func:`andrey.ges` (lower is better). Under a mixed-data setting, ``metadata["categorical"]`` lists the categorical columns it read. With a randomized ``indep_test``, ``metadata["seed"]`` is the seed used. Raises ------ TypeError If ``categorical`` is not a list of column names and positions, or ``knowledge`` is neither ``None`` nor a :class:`~andrey.Knowledge`. ValueError If an argument has the wrong type, lies outside its range, or is not one of its choices; the message names the method, the argument, what it accepts, and the value. Also if ``score_func`` and ``indep_test`` read different kinds of data, or if ``data`` or ``categorical`` does not suit the test or score, as for :func:`~andrey.pc` and :func:`~andrey.hc`. Also if the required edges of ``knowledge`` give a node more than ``max_parents`` parents, or if ``knowledge`` names a column ``data`` lacks or contradicts itself, as :class:`~andrey.Knowledge` lists. Warns ----- SearchLimitWarning When the search takes a given ``max_iter`` moves. DataTypeWarning As for :func:`~andrey.pc`, when a mixed-data setting finds no declared categorical column or a setting reads columns that look like category codes as numbers; once per process. See Also -------- andrey.rsmax2 : Other restrict and maximize phases. andrey.mmpc : The MMPC phase alone, for one variable or all. Notes ----- **When to use.** MMHC suits i.i.d. observational data with no unmeasured common causes, in which every independence follows from the graph (faithfulness) [1]_. Its default Fisher-Z test and BIC score assume continuous data with linear effects and Gaussian noise; with categorical or mixed columns, the defaults follow the declared column types, as for :func:`~andrey.pc` and :func:`~andrey.ges`. It is a hybrid, a constraint-based skeleton from conditional-independence tests followed by a score-based search over only the skeleton's pairs, designed for many variables with few parents and children each [1]_. It returns the CPDAG of the DAG the search stops at. When unmeasured common causes are plausible, use :func:`~andrey.gfci`; when the noise is non-Gaussian and every edge should be oriented, use :func:`~andrey.direct_lingam`. **How it works.** The MMPC phase estimates each variable's parents and children: a forward phase adds, one at a time, the candidate whose weakest association with the variable, over every conditioning set drawn from the members so far, is the strongest, and a backward phase drops each member some subset of the others separates (:func:`~andrey.mmpc`). A pair enters the skeleton when each variable is in the other's set, the symmetry correction of [1]_. The hill-climbing phase starts from the empty graph, or from the required edges, and adds, removes, or reverses one edge at a time while the score improves, with every pair outside the skeleton forbidden in both directions. The result is the CPDAG of the DAG it stops at. Ties between candidates in the MMPC phase and between moves in the hill-climbing phase go to the column whose rank, computed from the data, comes first, as for :func:`~andrey.hc`, so the result does not depend on the column order unless two columns are identical. The :doc:`column-order guide </docs/guides/column-order>` lists what reordering the columns does to each method. **Choosing the penalty.** The hill-climbing phase scores as :func:`~andrey.hc` does: the linear-Gaussian BIC charges a variable ``penalty_discount * log(n_samples)`` per parent plus the extended-BIC term ``2 * ebic_gamma * log C(n_variables - 1, n_parents)`` [2]_, and :func:`~andrey.ges` describes the choice. ``ebic_gamma=0.0`` with ``penalty_discount=1.0`` is the standard BIC. On simulated linear-Gaussian data with 20 to 400 variables and 200 to 4,000 rows, the default ``ebic_gamma=1.0`` made fewer or as many errors (SHD) as the standard BIC on average in 64 of 65 settings of graph, variables, and rows, and 0.2 more in the last (7.0 against 6.8 with 20 variables, mean degree 2, ``scale="unitless"``, and 1,000 rows); with 200 variables and 2,000 rows it made 49 errors against 73 (200 true edges). The gain is smaller than hill climbing's, since the MMPC phase has already left out most false edges. **Missing values.** A ``NaN`` in ``data`` raises ``ValueError``: its hill-climbing phase scores every variable over the same rows, and score terms over different rows do not add up to the score of one dataset. Drop the incomplete rows first, which suits values missing completely at random, or use :func:`~andrey.pc` or :func:`~andrey.fci`, whose tests delete rows per test. **Limitations.** Measured on simulated linear-Gaussian data with 20, 50, and 100 variables, 1,000 and 5,000 rows, and mean degree 2 and 4, with Fisher-z tests at alpha 0.05 and the BIC, on one core. In every setting the mean CPDAG errors stay below the empty graph's; the closest is at 20 variables and mean degree 4, with 29 to 31 pairs wrong against 40 for the empty graph. A fit took 0.05 to 1.8 s, the longest at 100 variables, 5,000 rows, and mean degree 4. An edge the MMPC phase misses is never added, and the hill-climbing phase stops at a local optimum. MMPC tests each candidate against every subset of the current members, so its cost grows exponentially with the size of a variable's parents-and-children set. References ---------- .. [1] Tsamardinos, I., Brown, L. E., and Aliferis, C. F. (2006). The max-min hill-climbing Bayesian network structure learning algorithm. Machine Learning 65(1), 31-78. .. [2] Chen, J., and Chen, Z. (2008). Extended Bayesian information criteria for model selection with large model spaces. Biometrika 95(3), 759-771. Examples -------- >>> import warnings >>> import numpy as np >>> from andrey import mmhc >>> rng = np.random.default_rng(0) >>> x = rng.standard_normal(500) >>> y = x + 0.1 * rng.standard_normal(500) >>> with warnings.catch_warnings(): ... warnings.simplefilter("ignore") ... out = mmhc(np.column_stack([x, y])) >>> out.structure.kind 'cpdag' """ return _fit( "mmhc", data, restrict="mmpc", maximize="hc", alpha=alpha, indep_test=indep_test, score_func=score_func, penalty_discount=penalty_discount, ebic_gamma=ebic_gamma, equivalent_sample_size=equivalent_sample_size, max_iter=max_iter, tabu_length=10, max_tabu=None, categorical=categorical, seed=seed, max_depth=max_depth, max_parents=max_parents, knowledge=knowledge, )
[docs] @method_spec("rsmax2") def rsmax2( data: npt.ArrayLike, *, restrict: str = "mmpc", maximize: str = "hc", alpha: float = 0.05, indep_test: str | None = None, score_func: str | None = None, penalty_discount: float = 1.0, ebic_gamma: float = 1.0, equivalent_sample_size: float = 1.0, max_iter: int | None = None, tabu_length: int = 10, max_tabu: int | None = None, categorical: Sequence[str | int] | None = None, seed: int | None = None, max_depth: int | None = None, max_parents: int | None = None, knowledge: Knowledge | None = None, ) -> StructureOutput: """Learn a CPDAG from observational data with a restrict phase and a maximize phase. The restrict phase learns the pairs that may be adjacent with conditional-independence tests; the maximize phase runs a score search over DAGs whose edges join only those pairs [1]_ [5]_. A small candidate set makes the score search faster on many variables. Parameters ---------- data : array-like of shape (n_samples, n_variables) Observed data, one row per sample. Coerced to ``float64``. A DataFrame's column names become the structure's ``labels``. restrict : {"mmpc", "iamb", "inter_iamb", "pc"}, default="mmpc" The restrict phase. ``"mmpc"`` keeps a pair when each variable is in the other's MMPC parents and children [2]_, as :func:`~andrey.mmhc` does. ``"iamb"`` and ``"inter_iamb"`` keep a pair when each variable is in the other's Markov blanket from IAMB or Inter-IAMB [3]_ and no subset of the smaller blanket separates the two, the skeleton of ``iamb(structure="skeleton")``, which drops the pairs of parents of a common child. ``"pc"`` keeps the skeleton of :func:`~andrey.pc`'s adjacency search [4]_. See Notes. maximize : {"hc", "tabu"}, default="hc" The maximize phase: :func:`~andrey.hc` or :func:`~andrey.tabu`. alpha : float, default=0.05 Significance level of the restrict phase's tests. Smaller values keep fewer pairs. indep_test : str or None, default=None Conditional-independence test of the restrict phase, any of :func:`~andrey.pc`'s. It must read the same kind of data as ``score_func``. ``None`` picks from the declared column types, as for :func:`~andrey.pc`. ``metadata["indep_test"]`` names the test the fit used: the one picked from the declared column types when this is ``None``. score_func : str or None, default=None Local score of the maximize phase, any of :func:`~andrey.hc`'s. ``None`` picks from the declared column types, as for :func:`~andrey.ges`. ``metadata["score_func"]`` names the score the fit used: the one picked from the declared column types when this is ``None``. penalty_discount : float, default=1.0 Multiplier on the BIC penalty, as for :func:`~andrey.hc`. BDeu ignores it. ebic_gamma : float, default=1.0 Weight on the extended-BIC term of the linear-Gaussian BIC: each variable's score adds ``2 * ebic_gamma * log C(n_variables - 1, n_parents)``, which grows with the number of parent sets a variable can choose from. Larger values give sparser graphs; ``0.0`` is the standard BIC. Must be finite and non-negative. The other scores ignore it. See Notes. equivalent_sample_size : float, default=1.0 The equivalent sample size of the BDeu score: how many rows the uniform prior over each variable's conditional distributions is worth. A larger value weighs the prior more against the data, and the graph can change with it. Must be finite and positive. Only ``"bdeu"`` uses it: passing it with another score raises ``ValueError``. max_iter : int or None, default=None Maximum moves of the maximize phase, at least ``1``; ``None`` sets no limit. tabu_length : int, default=10 With ``maximize="tabu"``, the number of most recently visited DAGs a move may not return to, at least ``1``, as for :func:`~andrey.tabu`; hill climbing ignores it. max_tabu : int or None, default=None With ``maximize="tabu"``, the non-improving moves allowed without a better DAG, from ``1`` to ``tabu_length``; ``None`` uses ``tabu_length``. Hill climbing ignores it. categorical : sequence of str or int, optional The categorical columns of ``data``, for a mixed-data test and score, as for :func:`~andrey.pc`. A continuous setting raises ``ValueError`` on a declared column. seed : int or None, default=None ``None``, the default, is the configured seed, ``ANDREY_SEED`` or ``0`` when it is unset, not a fresh random one, so a fit repeats. Seed for the random draws of ``indep_test``, which only ``"rcot"``, ``"cmiknn"``, and ``"gpdc"`` make; the other tests ignore it. With those tests, ``metadata["seed"]`` records the seed used. max_depth : int or None, default=None The maximum conditioning-set size of every conditional-independence test in the restrict phase, at least ``0``: ``0`` runs only unconditional tests, and ``None`` sets no limit. A smaller cap runs fewer tests and can keep pairs that a larger conditioning set would remove. max_parents : int or None, default=None A cap on every node's parents, at least ``0``: the score search takes no move that gives a node more than ``max_parents`` parents, so no DAG the returned CPDAG represents does (every DAG of a class has the same largest number of parents). A cap can stop the search short of the lowest-scoring graph. ``None`` sets no cap. knowledge : Knowledge or None, default=None Background knowledge, a :class:`~andrey.Knowledge`: required and forbidden edges, the pairs allowed to be adjacent, and temporal tiers, all honored. The maximize phase considers the pairs the restrict phase keeps and the pairs of the required edges, less the pairs the knowledge makes non-adjacent, and then honors the knowledge as :func:`~andrey.hc` does. The restrict phase reads the data alone. Returns ------- StructureOutput Wraps a ``cpdag`` :class:`~andrey.core.GraphStructure`; ``metadata["algorithm"]`` is ``"rsmax2"``, ``metadata["score"]`` the score of the DAG found, computed as for :func:`andrey.ges` (lower is better). Under a mixed-data setting, ``metadata["categorical"]`` lists the categorical columns it read. With a randomized ``indep_test``, ``metadata["seed"]`` is the seed used. Raises ------ TypeError If ``categorical`` is not a list of column names and positions, or ``knowledge`` is neither ``None`` nor a :class:`~andrey.Knowledge`. ValueError If an argument has the wrong type, lies outside its range, or is not one of its choices; the message names the method, the argument, what it accepts, and the value. Also if ``score_func`` is not a score ``maximize`` takes, if ``score_func`` and ``indep_test`` read different kinds of data, if ``max_tabu`` is greater than ``tabu_length``, or if ``data`` or ``categorical`` does not suit the test or score, as for :func:`~andrey.pc` and :func:`~andrey.hc`. Also if the required edges of ``knowledge`` give a node more than ``max_parents`` parents, or if ``knowledge`` names a column ``data`` lacks or contradicts itself, as :class:`~andrey.Knowledge` lists. Warns ----- SearchLimitWarning When the maximize phase takes a given ``max_iter`` moves. PerformanceWarning With ``restrict="pc"``, when a conditioning pass needs at least ten million tests, as for :func:`~andrey.pc`. DataTypeWarning As for :func:`~andrey.pc`, when a mixed-data setting finds no declared categorical column or a setting reads columns that look like category codes as numbers; once per process. See Also -------- andrey.mmhc : ``restrict="mmpc"`` with ``maximize="hc"``. Notes ----- **When to use.** The restrict-then-maximize search suits i.i.d. observational data with no unmeasured common causes, in which every independence follows from the graph (faithfulness) [2]_. Its default Fisher-Z test and BIC score assume continuous data with linear effects and Gaussian noise; with categorical or mixed columns, the defaults follow the declared column types, as for :func:`~andrey.pc` and :func:`~andrey.ges`. It is a hybrid, a constraint-based skeleton from the tests ``restrict`` names followed by the score search ``maximize`` names over only the skeleton's pairs, designed for many variables with few candidate neighbors each [1]_. It returns the CPDAG of the DAG the maximize phase ends with. When unmeasured common causes are plausible, use :func:`~andrey.gfci`; when the noise is non-Gaussian and every edge should be oriented, use :func:`~andrey.direct_lingam`. **How it works.** The restrict phase follows the sparse candidate idea of [1]_: tests narrow the pairs a score search must consider. Each choice finds every true adjacency when its tests are exact. The skeletons of MMPC, IAMB, Inter-IAMB, and PC then hold only the true adjacencies. A Markov blanket also holds the other parents of a common child, so IAMB and Inter-IAMB test each pair of their moral graph against subsets of the smaller blanket and drop the pairs that separate. The maximize phase starts from the empty graph, or from the required edges, with every pair outside the candidates forbidden in both directions, and returns the CPDAG of the DAG it ends with. :func:`~andrey.mmpc`, :func:`~andrey.iamb`, and :func:`~andrey.inter_iamb` describe their searches; ``"pc"`` runs :func:`~andrey.pc`'s adjacency search without orienting. Ties go to the column whose rank, computed from the data, comes first, as for :func:`~andrey.hc`, so the result does not depend on the column order unless two columns are identical. **Choosing the penalty.** The maximize phase scores as :func:`~andrey.hc` does: the linear-Gaussian BIC charges a variable ``penalty_discount * log(n_samples)`` per parent plus the extended-BIC term ``2 * ebic_gamma * log C(n_variables - 1, n_parents)`` [6]_, and :func:`~andrey.ges` describes the choice. ``ebic_gamma=0.0`` with ``penalty_discount=1.0`` is the standard BIC. With ``restrict="pc"`` and ``maximize="tabu"``, on simulated linear-Gaussian data with 20 to 400 variables and 200 to 4,000 rows, the default ``ebic_gamma=1.0`` made fewer or as many errors (SHD) as the standard BIC on average in 63 of 65 settings of graph, variables, and rows, and more in two: 38.0 against 36.3 on the 46-variable ECOLI70 network with 1,000 simulated rows, where one of three draws moved by 7, and 39.2 against 38.8 with 50 variables, mean degree 4, ``scale="unitless"``, and 1,000 rows. With 200 variables and 2,000 rows it made 42 errors against 65 (200 true edges). The default ``restrict="mmpc"`` with ``maximize="hc"`` is :func:`~andrey.mmhc`'s search, whose numbers are given there. **Missing values.** A ``NaN`` in ``data`` raises ``ValueError``: its score phase scores every variable over the same rows, and score terms over different rows do not add up to the score of one dataset. Drop the incomplete rows first, which suits values missing completely at random, or use :func:`~andrey.pc` or :func:`~andrey.fci`, whose tests delete rows per test. **Limitations.** Measured on simulated linear-Gaussian data with 20, 50, and 100 variables, 1,000 and 5,000 rows, and mean degree 2 and 4, with Fisher-z tests at alpha 0.05 and the BIC, on one core, with ``restrict="mmpc"`` and ``"iamb"`` and ``maximize="hc"``. In every setting the mean CPDAG errors stay below the empty graph's; the closest is at 20 variables and mean degree 4, with 29 to 31 pairs wrong for ``"mmpc"`` and 21 to 24 for ``"iamb"``, against 40 for the empty graph. A fit took 0.04 to 3.5 s with ``"mmpc"`` and 0.07 to 8.8 s with ``"iamb"``, the longest at 100 variables, 5,000 rows, and mean degree 4. An edge the restrict phase misses is never added, and the maximize phase stops at a local optimum. MMPC tests each candidate against every subset of the current members, so its cost grows exponentially with the size of a variable's parents-and-children set. IAMB and Inter-IAMB condition on the whole current blanket, so each of their tests needs more rows as the blankets grow. References ---------- .. [1] Friedman, N., Nachman, I., and Pe'er, D. (1999). Learning Bayesian network structure from massive datasets: the "sparse candidate" algorithm. UAI, 206-215. .. [2] Tsamardinos, I., Brown, L. E., and Aliferis, C. F. (2006). The max-min hill-climbing Bayesian network structure learning algorithm. Machine Learning 65(1), 31-78. .. [3] Tsamardinos, I., Aliferis, C. F., and Statnikov, A. (2003). Algorithms for large scale Markov blanket discovery. FLAIRS, 376-380. .. [4] Colombo, D., and Maathuis, M. H. (2014). Order-independent constraint-based causal structure learning. JMLR 15, 3921-3962. .. [5] Scutari, M. (2010). Learning Bayesian networks with the bnlearn R package. Journal of Statistical Software 35(3). https://doi.org/10.18637/jss.v035.i03 .. [6] Chen, J., and Chen, Z. (2008). Extended Bayesian information criteria for model selection with large model spaces. Biometrika 95(3), 759-771. Examples -------- >>> import warnings >>> import numpy as np >>> from andrey import rsmax2 >>> rng = np.random.default_rng(0) >>> x = rng.standard_normal(500) >>> y = x + 0.1 * rng.standard_normal(500) >>> with warnings.catch_warnings(): ... warnings.simplefilter("ignore") ... out = rsmax2(np.column_stack([x, y]), restrict="pc", maximize="tabu") >>> out.structure.kind 'cpdag' """ return _fit( "rsmax2", data, restrict=restrict, maximize=maximize, alpha=alpha, indep_test=indep_test, score_func=score_func, penalty_discount=penalty_discount, ebic_gamma=ebic_gamma, equivalent_sample_size=equivalent_sample_size, max_iter=max_iter, tabu_length=tabu_length, max_tabu=max_tabu, categorical=categorical, seed=seed, max_depth=max_depth, max_parents=max_parents, knowledge=knowledge, )