Greedy rule list. Greedily splits on one feature at a time along a single path. Tries to find rules which maximize the probability of class 1. Currently only supports binary classification.

'''Greedy rule list.
Greedily splits on one feature at a time along a single path.
Tries to find rules which maximize the probability of class 1.
Currently only supports binary classification.
'''

import math
from copy import deepcopy

import numpy as np
from sklearn.base import BaseEstimator, ClassifierMixin
from sklearn.utils.multiclass import unique_labels
from sklearn.utils.validation import check_array, check_is_fitted
from sklearn.tree import DecisionTreeClassifier
from imodels.rule_list.rule_list import RuleList
from imodels.util.arguments import check_fit_arguments


class GreedyRuleListClassifier(BaseEstimator, RuleList, ClassifierMixin):
    def __init__(self, max_depth: int = 5, class_weight=None,
                 criterion: str = 'gini'):
        '''
        Params
        ------
        max_depth
            Maximum depth the list can achieve
        criterion: str
            Criterion used to split
            'gini', 'entropy', or 'log_loss'
        '''

        self.max_depth = max_depth
        self.class_weight = class_weight
        self.criterion = criterion
        self.depth = 0  # tracks the fitted depth

    def fit(self, X, y, depth: int = 0, feature_names=None, verbose=False):
        """
        Params
        ------
        X: array_like
            Feature set
        y: array_like
            target variable
        depth
            the depth of the current layer (used to recurse)
        """
        X, y, feature_names = check_fit_arguments(self, X, y, feature_names)
        return self.fit_node_recursive(X, y, depth=0, verbose=verbose)

    def fit_node_recursive(self, X, y, depth: int, verbose):

        # base case 1: no data in this group
        if y.size == 0:
            return []

        # base case 2: all y is the same in this group
        elif np.all(y == y[0]):
            return [{'val': y[0], 'num_pts': y.size}]

         # base case 3: max depth reached
        elif depth == self.max_depth:
            return [{'val': np.mean(y), 'num_pts': y.size}]

        # recursively generate rule list
        else:

            # find a split with the best value for the criterion
            m = DecisionTreeClassifier(max_depth=1, criterion=self.criterion)
            m.fit(X, y)
            col = m.tree_.feature[0]
            cutoff = m.tree_.threshold[0]
            # col, cutoff, criterion_val = self._find_best_split(X, y)
            if col == -2:
                return []
                
            y_left = y[X[:, col] < cutoff]  # left-hand side data
            y_right = y[X[:, col] >= cutoff]  # right-hand side data


            # put higher probability of class 1 on the right-hand side
            if len(y_left) > 0 and np.mean(y_left) > np.mean(y_right):
                flip = True
                tmp = deepcopy(y_left)
                y_left = deepcopy(y_right)
                y_right = tmp
                x_left = X[X[:, col] >= cutoff]
            else:
                flip = False
                x_left = X[X[:, col] < cutoff]

            # print
            if verbose:
                print(
                    f'{np.mean(100 * y):.2f} -> {self.feature_names_[col]} -> {np.mean(100 * y_left):.2f} ({y_left.size}) {np.mean(100 * y_right):.2f} ({y_right.size})')

            # save info
            par_node = [{
                'col': self.feature_names_[col],
                'index_col': col,
                'cutoff': cutoff,
                'val': np.mean(y_left),  # will be the values before splitting in the next lower level
                'flip': flip,
                'val_right': np.mean(y_right),
                'num_pts': y.size,
                'num_pts_right': y_right.size
            }]

            # generate tree for the non-leaf data
            par_node = par_node + \
                self.fit_node_recursive(x_left, y_left, depth + 1, verbose=verbose)

            self.depth += 1  # increase the depth since we call fit once
            self.rules_ = par_node
            self.complexity_ = len(self.rules_)
            self.classes_ = unique_labels(y)
            return par_node

    def predict_proba(self, X):
        check_is_fitted(self)
        X = check_array(X)
        n = X.shape[0]
        probs = np.zeros(n)
        for i in range(n):
            x = X[i]
            for j, rule in enumerate(self.rules_):
                if j == len(self.rules_) - 1:
                    probs[i] = rule['val']
                    continue
                regular_condition = x[rule["index_col"]] >= rule["cutoff"]
                flipped_condition = x[rule["index_col"]] < rule["cutoff"]
                condition = flipped_condition if rule["flip"] else regular_condition
                if condition:
                    probs[i] = rule['val_right']
                    break
        return np.vstack((1 - probs, probs)).transpose()  # probs (n, 2)

    def predict(self, X):
        check_is_fitted(self)
        X = check_array(X)
        return np.argmax(self.predict_proba(X), axis=1)

    """
    def __str__(self):
        # s = ''
        # for rule in self.rules_:
        #     s += f"mean {rule['val'].round(3)} ({rule['num_pts']} pts)\n"
        #     if 'col' in rule:
        #         s += f"if {rule['col']} >= {rule['cutoff']} then {rule['val_right'].round(3)} ({rule['num_pts_right']} pts)\n"
        # return s
    """

    def __str__(self):
        '''Print out the list in a nice way
        '''
        s = '> ------------------------------\n> Greedy Rule List\n> ------------------------------\n'

        def red(s):
            # return f"\033[91m{s}\033[00m"
            return s

        def cyan(s):
            # return f"\033[96m{s}\033[00m"
            return s

        def rule_name(rule):
            if rule['flip']:
                return '~' + rule['col']
            return rule['col']

        # rule = self.rules_[0]
        #     s += f"{red((100 * rule['val']).round(3))}% IwI ({rule['num_pts']} pts)\n"
        for rule in self.rules_:
            s += u'\u2193\n' + f"{cyan((100 * rule['val']).round(2))}% risk ({rule['num_pts']} pts)\n"
            #         s += f"\t{'Else':>45} => {cyan((100 * rule['val']).round(2)):>6}% IwI ({rule['val'] * rule['num_pts']:.0f}/{rule['num_pts']} pts)\n"
            if 'col' in rule:
                #             prefix = f"if {rule['col']} >= {rule['cutoff']}"
                prefix = f"if {rule_name(rule)}"
                val = f"{100 * rule['val_right'].round(3)}"
                s += f"\t{prefix} ==> {red(val)}% risk ({rule['num_pts_right']} pts)\n"
        # rule = self.rules_[-1]
        #     s += f"{red((100 * rule['val']).round(3))}% IwI ({rule['num_pts']} pts)\n"
        return s

    ######## HERE ONWARDS CUSTOM SPLITTING (DEPRECATED IN FAVOR OF SKLEARN STUMP) ########
    ######################################################################################
    def _find_best_split(self, x, y):
        """
        Find the best split from all features
        returns: the column to split on, the cutoff value, and the actual criterion_value
        """
        col = None
        min_criterion_val = 1e10
        cutoff = None

        # iterating through each feature
        for i, c in enumerate(x.T):

            # find the best split of that feature
            criterion_val, cur_cutoff = self._split_on_feature(c, y)

            # found perfect cutoff
            if criterion_val == 0:
                return i, cur_cutoff, criterion_val

            # check if it's best so far
            elif criterion_val <= min_criterion_val:
                min_criterion_val = criterion_val
                col = i
                cutoff = cur_cutoff
        return col, cutoff, min_criterion_val

    def _split_on_feature(self, col, y):
        """
        col: the column we split on
        y: target var
        """
        min_criterion_val = 1e10
        cutoff = 0.5

        # iterate through each value in the column
        for value in np.unique(col):
            # separate y into 2 groups
            y_predict = col < value

            # get criterion val of this split
            criterion_val = self._weighted_criterion(y_predict, y)

            # check if it's the smallest one so far
            if criterion_val <= min_criterion_val:
                min_criterion_val = criterion_val
                cutoff = value
        return min_criterion_val, cutoff

    def _weighted_criterion(self, split_decision, y_real):
        """Returns criterion calculated over a split
        split decision, True/False, and y_true can be multi class
        """
        if split_decision.shape[0] != y_real.shape[0]:
            print('They have to be the same length')
            return None

        # choose the splitting criterion
        if self.criterion == 'entropy':
            criterion_func = self._entropy_criterion
        elif self.criterion == 'gini':
            criterion_func = self._gini_criterion
        elif self.criterion == 'neg_corr':
            return self._neg_corr_criterion(split_decision, y_real)

        # left-hand side criterion
        s_left = criterion_func(y_real[split_decision])

        # right-hand side criterion
        s_right = criterion_func(y_real[~split_decision])

        # overall criterion, again weighted average
        n = y_real.shape[0]
        if self.class_weight is not None:
            sample_weights = np.ones(n)
            for c in self.class_weight.keys():
                idxs_c = y_real == c
                sample_weights[idxs_c] = self.class_weight[c]
            total_weight = np.sum(sample_weights)
            weight_left = np.sum(sample_weights[split_decision]) / total_weight
            # weight_right = np.sum(sample_weights[~split_decision]) / total_weight
        else:
            tot_left_samples = np.sum(split_decision == 1)
            weight_left = tot_left_samples / n

        s = weight_left * s_left + (1 - weight_left) * s_right
        return s

    def _gini_criterion(self, y):
        '''Returns gini index for one node
        = sum(pc * (1 – pc))
        '''
        s = 0
        n = y.shape[0]
        classes = np.unique(y)

        # for each class, get entropy
        for c in classes:
            # weights for each class
            n_c = np.sum(y == c)
            p_c = n_c / n

            # weighted avg
            s += p_c * (1 - p_c)

        return s

    def _entropy_criterion(self, y):
        """Returns entropy of a divided group of data
        Data may have multiple classes
        """
        s = 0
        n = len(y)
        classes = set(y)

        # for each class, get entropy
        for c in classes:
            # weights for each class
            weight = sum(y == c) / n

            def _entropy_from_counts(c1, c2):
                """Returns entropy of a group of data
                c1: count of one class
                c2: count of another class
                """
                if c1 == 0 or c2 == 0:  # when there is only one class in the group, entropy is 0
                    return 0

                def _entropy_func(p): return -p * math.log(p, 2)

                p1 = c1 * 1.0 / (c1 + c2)
                p2 = c2 * 1.0 / (c1 + c2)
                return _entropy_func(p1) + _entropy_func(p2)

            # weighted avg
            s += weight * _entropy_from_counts(sum(y == c), sum(y != c))
        return s

    def _neg_corr_criterion(self, split_decision, y):
        '''Returns negative correlation between y
        and the binary splitting variable split_decision
        y must be binary
        '''
        if np.unique(y).size < 2:
            return 0
        elif np.unique(y).size != 2:
            print('y must be binary output for corr criterion')

        # y should be 1 more often on the "right side" of the split
        if y.sum() < y.size / 2:
            y = 1 - y

        return -1 * np.corrcoef(split_decision.astype(np.int), y)[0, 1]

Classes

class GreedyRuleListClassifier (max_depth: int = 5, class_weight=None, criterion: str = 'gini')

Base class for all estimators in scikit-learn.

Inheriting from this class provides default implementations of:

• setting and getting parameters used by GridSearchCV and friends;
• textual and HTML representation displayed in terminals and IDEs;
• estimator serialization;
• parameters validation;
• data validation;
• feature names validation.

Read more in the :ref:User Guide <rolling_your_own_estimator>.

Notes

All estimators should specify all the parameters that can be set at the class level in their __init__ as explicit keyword arguments (no *args or **kwargs).

Examples

>>> import numpy as np
>>> from sklearn.base import BaseEstimator
>>> class MyEstimator(BaseEstimator):
...     def __init__(self, *, param=1):
...         self.param = param
...     def fit(self, X, y=None):
...         self.is_fitted_ = True
...         return self
...     def predict(self, X):
...         return np.full(shape=X.shape[0], fill_value=self.param)
>>> estimator = MyEstimator(param=2)
>>> estimator.get_params()
{'param': 2}
>>> X = np.array([[1, 2], [2, 3], [3, 4]])
>>> y = np.array([1, 0, 1])
>>> estimator.fit(X, y).predict(X)
array([2, 2, 2])
>>> estimator.set_params(param=3).fit(X, y).predict(X)
array([3, 3, 3])

Params

max_depth Maximum depth the list can achieve criterion: str Criterion used to split 'gini', 'entropy', or 'log_loss'

Expand source code

class GreedyRuleListClassifier(BaseEstimator, RuleList, ClassifierMixin):
    def __init__(self, max_depth: int = 5, class_weight=None,
                 criterion: str = 'gini'):
        '''
        Params
        ------
        max_depth
            Maximum depth the list can achieve
        criterion: str
            Criterion used to split
            'gini', 'entropy', or 'log_loss'
        '''

        self.max_depth = max_depth
        self.class_weight = class_weight
        self.criterion = criterion
        self.depth = 0  # tracks the fitted depth

    def fit(self, X, y, depth: int = 0, feature_names=None, verbose=False):
        """
        Params
        ------
        X: array_like
            Feature set
        y: array_like
            target variable
        depth
            the depth of the current layer (used to recurse)
        """
        X, y, feature_names = check_fit_arguments(self, X, y, feature_names)
        return self.fit_node_recursive(X, y, depth=0, verbose=verbose)

    def fit_node_recursive(self, X, y, depth: int, verbose):

        # base case 1: no data in this group
        if y.size == 0:
            return []

        # base case 2: all y is the same in this group
        elif np.all(y == y[0]):
            return [{'val': y[0], 'num_pts': y.size}]

         # base case 3: max depth reached
        elif depth == self.max_depth:
            return [{'val': np.mean(y), 'num_pts': y.size}]

        # recursively generate rule list
        else:

            # find a split with the best value for the criterion
            m = DecisionTreeClassifier(max_depth=1, criterion=self.criterion)
            m.fit(X, y)
            col = m.tree_.feature[0]
            cutoff = m.tree_.threshold[0]
            # col, cutoff, criterion_val = self._find_best_split(X, y)
            if col == -2:
                return []
                
            y_left = y[X[:, col] < cutoff]  # left-hand side data
            y_right = y[X[:, col] >= cutoff]  # right-hand side data


            # put higher probability of class 1 on the right-hand side
            if len(y_left) > 0 and np.mean(y_left) > np.mean(y_right):
                flip = True
                tmp = deepcopy(y_left)
                y_left = deepcopy(y_right)
                y_right = tmp
                x_left = X[X[:, col] >= cutoff]
            else:
                flip = False
                x_left = X[X[:, col] < cutoff]

            # print
            if verbose:
                print(
                    f'{np.mean(100 * y):.2f} -> {self.feature_names_[col]} -> {np.mean(100 * y_left):.2f} ({y_left.size}) {np.mean(100 * y_right):.2f} ({y_right.size})')

            # save info
            par_node = [{
                'col': self.feature_names_[col],
                'index_col': col,
                'cutoff': cutoff,
                'val': np.mean(y_left),  # will be the values before splitting in the next lower level
                'flip': flip,
                'val_right': np.mean(y_right),
                'num_pts': y.size,
                'num_pts_right': y_right.size
            }]

            # generate tree for the non-leaf data
            par_node = par_node + \
                self.fit_node_recursive(x_left, y_left, depth + 1, verbose=verbose)

            self.depth += 1  # increase the depth since we call fit once
            self.rules_ = par_node
            self.complexity_ = len(self.rules_)
            self.classes_ = unique_labels(y)
            return par_node

    def predict_proba(self, X):
        check_is_fitted(self)
        X = check_array(X)
        n = X.shape[0]
        probs = np.zeros(n)
        for i in range(n):
            x = X[i]
            for j, rule in enumerate(self.rules_):
                if j == len(self.rules_) - 1:
                    probs[i] = rule['val']
                    continue
                regular_condition = x[rule["index_col"]] >= rule["cutoff"]
                flipped_condition = x[rule["index_col"]] < rule["cutoff"]
                condition = flipped_condition if rule["flip"] else regular_condition
                if condition:
                    probs[i] = rule['val_right']
                    break
        return np.vstack((1 - probs, probs)).transpose()  # probs (n, 2)

    def predict(self, X):
        check_is_fitted(self)
        X = check_array(X)
        return np.argmax(self.predict_proba(X), axis=1)

    """
    def __str__(self):
        # s = ''
        # for rule in self.rules_:
        #     s += f"mean {rule['val'].round(3)} ({rule['num_pts']} pts)\n"
        #     if 'col' in rule:
        #         s += f"if {rule['col']} >= {rule['cutoff']} then {rule['val_right'].round(3)} ({rule['num_pts_right']} pts)\n"
        # return s
    """

    def __str__(self):
        '''Print out the list in a nice way
        '''
        s = '> ------------------------------\n> Greedy Rule List\n> ------------------------------\n'

        def red(s):
            # return f"\033[91m{s}\033[00m"
            return s

        def cyan(s):
            # return f"\033[96m{s}\033[00m"
            return s

        def rule_name(rule):
            if rule['flip']:
                return '~' + rule['col']
            return rule['col']

        # rule = self.rules_[0]
        #     s += f"{red((100 * rule['val']).round(3))}% IwI ({rule['num_pts']} pts)\n"
        for rule in self.rules_:
            s += u'\u2193\n' + f"{cyan((100 * rule['val']).round(2))}% risk ({rule['num_pts']} pts)\n"
            #         s += f"\t{'Else':>45} => {cyan((100 * rule['val']).round(2)):>6}% IwI ({rule['val'] * rule['num_pts']:.0f}/{rule['num_pts']} pts)\n"
            if 'col' in rule:
                #             prefix = f"if {rule['col']} >= {rule['cutoff']}"
                prefix = f"if {rule_name(rule)}"
                val = f"{100 * rule['val_right'].round(3)}"
                s += f"\t{prefix} ==> {red(val)}% risk ({rule['num_pts_right']} pts)\n"
        # rule = self.rules_[-1]
        #     s += f"{red((100 * rule['val']).round(3))}% IwI ({rule['num_pts']} pts)\n"
        return s

    ######## HERE ONWARDS CUSTOM SPLITTING (DEPRECATED IN FAVOR OF SKLEARN STUMP) ########
    ######################################################################################
    def _find_best_split(self, x, y):
        """
        Find the best split from all features
        returns: the column to split on, the cutoff value, and the actual criterion_value
        """
        col = None
        min_criterion_val = 1e10
        cutoff = None

        # iterating through each feature
        for i, c in enumerate(x.T):

            # find the best split of that feature
            criterion_val, cur_cutoff = self._split_on_feature(c, y)

            # found perfect cutoff
            if criterion_val == 0:
                return i, cur_cutoff, criterion_val

            # check if it's best so far
            elif criterion_val <= min_criterion_val:
                min_criterion_val = criterion_val
                col = i
                cutoff = cur_cutoff
        return col, cutoff, min_criterion_val

    def _split_on_feature(self, col, y):
        """
        col: the column we split on
        y: target var
        """
        min_criterion_val = 1e10
        cutoff = 0.5

        # iterate through each value in the column
        for value in np.unique(col):
            # separate y into 2 groups
            y_predict = col < value

            # get criterion val of this split
            criterion_val = self._weighted_criterion(y_predict, y)

            # check if it's the smallest one so far
            if criterion_val <= min_criterion_val:
                min_criterion_val = criterion_val
                cutoff = value
        return min_criterion_val, cutoff

    def _weighted_criterion(self, split_decision, y_real):
        """Returns criterion calculated over a split
        split decision, True/False, and y_true can be multi class
        """
        if split_decision.shape[0] != y_real.shape[0]:
            print('They have to be the same length')
            return None

        # choose the splitting criterion
        if self.criterion == 'entropy':
            criterion_func = self._entropy_criterion
        elif self.criterion == 'gini':
            criterion_func = self._gini_criterion
        elif self.criterion == 'neg_corr':
            return self._neg_corr_criterion(split_decision, y_real)

        # left-hand side criterion
        s_left = criterion_func(y_real[split_decision])

        # right-hand side criterion
        s_right = criterion_func(y_real[~split_decision])

        # overall criterion, again weighted average
        n = y_real.shape[0]
        if self.class_weight is not None:
            sample_weights = np.ones(n)
            for c in self.class_weight.keys():
                idxs_c = y_real == c
                sample_weights[idxs_c] = self.class_weight[c]
            total_weight = np.sum(sample_weights)
            weight_left = np.sum(sample_weights[split_decision]) / total_weight
            # weight_right = np.sum(sample_weights[~split_decision]) / total_weight
        else:
            tot_left_samples = np.sum(split_decision == 1)
            weight_left = tot_left_samples / n

        s = weight_left * s_left + (1 - weight_left) * s_right
        return s

    def _gini_criterion(self, y):
        '''Returns gini index for one node
        = sum(pc * (1 – pc))
        '''
        s = 0
        n = y.shape[0]
        classes = np.unique(y)

        # for each class, get entropy
        for c in classes:
            # weights for each class
            n_c = np.sum(y == c)
            p_c = n_c / n

            # weighted avg
            s += p_c * (1 - p_c)

        return s

    def _entropy_criterion(self, y):
        """Returns entropy of a divided group of data
        Data may have multiple classes
        """
        s = 0
        n = len(y)
        classes = set(y)

        # for each class, get entropy
        for c in classes:
            # weights for each class
            weight = sum(y == c) / n

            def _entropy_from_counts(c1, c2):
                """Returns entropy of a group of data
                c1: count of one class
                c2: count of another class
                """
                if c1 == 0 or c2 == 0:  # when there is only one class in the group, entropy is 0
                    return 0

                def _entropy_func(p): return -p * math.log(p, 2)

                p1 = c1 * 1.0 / (c1 + c2)
                p2 = c2 * 1.0 / (c1 + c2)
                return _entropy_func(p1) + _entropy_func(p2)

            # weighted avg
            s += weight * _entropy_from_counts(sum(y == c), sum(y != c))
        return s

    def _neg_corr_criterion(self, split_decision, y):
        '''Returns negative correlation between y
        and the binary splitting variable split_decision
        y must be binary
        '''
        if np.unique(y).size < 2:
            return 0
        elif np.unique(y).size != 2:
            print('y must be binary output for corr criterion')

        # y should be 1 more often on the "right side" of the split
        if y.sum() < y.size / 2:
            y = 1 - y

        return -1 * np.corrcoef(split_decision.astype(np.int), y)[0, 1]

Ancestors

• sklearn.base.BaseEstimator
• sklearn.utils._estimator_html_repr._HTMLDocumentationLinkMixin
• sklearn.utils._metadata_requests._MetadataRequester
• RuleList
• sklearn.base.ClassifierMixin

Subclasses

• OptimalRuleListClassifier
• OneRClassifier

Methods

def fit(self, X, y, depth: int = 0, feature_names=None, verbose=False)

Params

X: array_like Feature set y: array_like target variable depth the depth of the current layer (used to recurse)

Expand source code

def fit(self, X, y, depth: int = 0, feature_names=None, verbose=False):
    """
    Params
    ------
    X: array_like
        Feature set
    y: array_like
        target variable
    depth
        the depth of the current layer (used to recurse)
    """
    X, y, feature_names = check_fit_arguments(self, X, y, feature_names)
    return self.fit_node_recursive(X, y, depth=0, verbose=verbose)

def fit_node_recursive(self, X, y, depth: int, verbose)

Expand source code

def fit_node_recursive(self, X, y, depth: int, verbose):

    # base case 1: no data in this group
    if y.size == 0:
        return []

    # base case 2: all y is the same in this group
    elif np.all(y == y[0]):
        return [{'val': y[0], 'num_pts': y.size}]

     # base case 3: max depth reached
    elif depth == self.max_depth:
        return [{'val': np.mean(y), 'num_pts': y.size}]

    # recursively generate rule list
    else:

        # find a split with the best value for the criterion
        m = DecisionTreeClassifier(max_depth=1, criterion=self.criterion)
        m.fit(X, y)
        col = m.tree_.feature[0]
        cutoff = m.tree_.threshold[0]
        # col, cutoff, criterion_val = self._find_best_split(X, y)
        if col == -2:
            return []
            
        y_left = y[X[:, col] < cutoff]  # left-hand side data
        y_right = y[X[:, col] >= cutoff]  # right-hand side data


        # put higher probability of class 1 on the right-hand side
        if len(y_left) > 0 and np.mean(y_left) > np.mean(y_right):
            flip = True
            tmp = deepcopy(y_left)
            y_left = deepcopy(y_right)
            y_right = tmp
            x_left = X[X[:, col] >= cutoff]
        else:
            flip = False
            x_left = X[X[:, col] < cutoff]

        # print
        if verbose:
            print(
                f'{np.mean(100 * y):.2f} -> {self.feature_names_[col]} -> {np.mean(100 * y_left):.2f} ({y_left.size}) {np.mean(100 * y_right):.2f} ({y_right.size})')

        # save info
        par_node = [{
            'col': self.feature_names_[col],
            'index_col': col,
            'cutoff': cutoff,
            'val': np.mean(y_left),  # will be the values before splitting in the next lower level
            'flip': flip,
            'val_right': np.mean(y_right),
            'num_pts': y.size,
            'num_pts_right': y_right.size
        }]

        # generate tree for the non-leaf data
        par_node = par_node + \
            self.fit_node_recursive(x_left, y_left, depth + 1, verbose=verbose)

        self.depth += 1  # increase the depth since we call fit once
        self.rules_ = par_node
        self.complexity_ = len(self.rules_)
        self.classes_ = unique_labels(y)
        return par_node

def predict(self, X)

Expand source code

def predict(self, X):
    check_is_fitted(self)
    X = check_array(X)
    return np.argmax(self.predict_proba(X), axis=1)

def predict_proba(self, X)

Expand source code

def predict_proba(self, X):
    check_is_fitted(self)
    X = check_array(X)
    n = X.shape[0]
    probs = np.zeros(n)
    for i in range(n):
        x = X[i]
        for j, rule in enumerate(self.rules_):
            if j == len(self.rules_) - 1:
                probs[i] = rule['val']
                continue
            regular_condition = x[rule["index_col"]] >= rule["cutoff"]
            flipped_condition = x[rule["index_col"]] < rule["cutoff"]
            condition = flipped_condition if rule["flip"] else regular_condition
            if condition:
                probs[i] = rule['val_right']
                break
    return np.vstack((1 - probs, probs)).transpose()  # probs (n, 2)

def set_fit_request(self: GreedyRuleListClassifier, *, depth: Union[bool, ForwardRef(None), str] = '$UNCHANGED$', feature_names: Union[bool, ForwardRef(None), str] = '$UNCHANGED$', verbose: Union[bool, ForwardRef(None), str] = '$UNCHANGED$') ‑> GreedyRuleListClassifier

Request metadata passed to the fit method.

Note that this method is only relevant if enable_metadata_routing=True (see :func:sklearn.set_config). Please see :ref:User Guide <metadata_routing> on how the routing mechanism works.

The options for each parameter are:

• True: metadata is requested, and passed to fit if provided. The request is ignored if metadata is not provided.

• False: metadata is not requested and the meta-estimator will not pass it to fit.

• None: metadata is not requested, and the meta-estimator will raise an error if the user provides it.

• str: metadata should be passed to the meta-estimator with this given alias instead of the original name.

The default (sklearn.utils.metadata_routing.UNCHANGED) retains the existing request. This allows you to change the request for some parameters and not others.

Added in version: 1.3

Note

This method is only relevant if this estimator is used as a sub-estimator of a meta-estimator, e.g. used inside a :class:~sklearn.pipeline.Pipeline. Otherwise it has no effect.

Parameters

depth : str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED

Metadata routing for depth parameter in fit.

feature_names : str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED

Metadata routing for feature_names parameter in fit.

verbose : str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED

Metadata routing for verbose parameter in fit.

Returns

self : object

The updated object.

Expand source code

def func(*args, **kw):
    """Updates the request for provided parameters

    This docstring is overwritten below.
    See REQUESTER_DOC for expected functionality
    """
    if not _routing_enabled():
        raise RuntimeError(
            "This method is only available when metadata routing is enabled."
            " You can enable it using"
            " sklearn.set_config(enable_metadata_routing=True)."
        )

    if self.validate_keys and (set(kw) - set(self.keys)):
        raise TypeError(
            f"Unexpected args: {set(kw) - set(self.keys)} in {self.name}. "
            f"Accepted arguments are: {set(self.keys)}"
        )

    # This makes it possible to use the decorated method as an unbound method,
    # for instance when monkeypatching.
    # https://github.com/scikit-learn/scikit-learn/issues/28632
    if instance is None:
        _instance = args[0]
        args = args[1:]
    else:
        _instance = instance

    # Replicating python's behavior when positional args are given other than
    # `self`, and `self` is only allowed if this method is unbound.
    if args:
        raise TypeError(
            f"set_{self.name}_request() takes 0 positional argument but"
            f" {len(args)} were given"
        )

    requests = _instance._get_metadata_request()
    method_metadata_request = getattr(requests, self.name)

    for prop, alias in kw.items():
        if alias is not UNCHANGED:
            method_metadata_request.add_request(param=prop, alias=alias)
    _instance._metadata_request = requests

    return _instance

def set_score_request(self: GreedyRuleListClassifier, *, sample_weight: Union[bool, ForwardRef(None), str] = '$UNCHANGED$') ‑> GreedyRuleListClassifier

Request metadata passed to the score method.

Note that this method is only relevant if enable_metadata_routing=True (see :func:sklearn.set_config). Please see :ref:User Guide <metadata_routing> on how the routing mechanism works.

The options for each parameter are:

• True: metadata is requested, and passed to score if provided. The request is ignored if metadata is not provided.

• False: metadata is not requested and the meta-estimator will not pass it to score.

• None: metadata is not requested, and the meta-estimator will raise an error if the user provides it.

• str: metadata should be passed to the meta-estimator with this given alias instead of the original name.

The default (sklearn.utils.metadata_routing.UNCHANGED) retains the existing request. This allows you to change the request for some parameters and not others.

Added in version: 1.3

Note

This method is only relevant if this estimator is used as a sub-estimator of a meta-estimator, e.g. used inside a :class:~sklearn.pipeline.Pipeline. Otherwise it has no effect.

Parameters

sample_weight : str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED

Metadata routing for sample_weight parameter in score.

Returns

self : object

The updated object.

Expand source code

def func(*args, **kw):
    """Updates the request for provided parameters

    This docstring is overwritten below.
    See REQUESTER_DOC for expected functionality
    """
    if not _routing_enabled():
        raise RuntimeError(
            "This method is only available when metadata routing is enabled."
            " You can enable it using"
            " sklearn.set_config(enable_metadata_routing=True)."
        )

    if self.validate_keys and (set(kw) - set(self.keys)):
        raise TypeError(
            f"Unexpected args: {set(kw) - set(self.keys)} in {self.name}. "
            f"Accepted arguments are: {set(self.keys)}"
        )

    # This makes it possible to use the decorated method as an unbound method,
    # for instance when monkeypatching.
    # https://github.com/scikit-learn/scikit-learn/issues/28632
    if instance is None:
        _instance = args[0]
        args = args[1:]
    else:
        _instance = instance

    # Replicating python's behavior when positional args are given other than
    # `self`, and `self` is only allowed if this method is unbound.
    if args:
        raise TypeError(
            f"set_{self.name}_request() takes 0 positional argument but"
            f" {len(args)} were given"
        )

    requests = _instance._get_metadata_request()
    method_metadata_request = getattr(requests, self.name)

    for prop, alias in kw.items():
        if alias is not UNCHANGED:
            method_metadata_request.add_request(param=prop, alias=alias)
    _instance._metadata_request = requests

    return _instance