`diffprivlib.models`

Machine learning models with differential privacy

Classification models

Gaussian Naive Bayes

class diffprivlib.models.GaussianNB(*, epsilon=1.0, bounds=None, priors=None, var_smoothing=1e-09, random_state=None, accountant=None)[source]

Gaussian Naive Bayes (GaussianNB) with differential privacy

Inherits the sklearn.naive_bayes.GaussianNB class from Scikit Learn and adds noise to satisfy differential privacy to the learned means and variances. Adapted from the work presented in [VSB13].

Parameters:

epsilon (float, default: 1.0) – Privacy parameter $\epsilon$ for the model.
bounds (tuple, optional) – Bounds of the data, provided as a tuple of the form (min, max). min and max can either be scalars, covering the min/max of the entire data, or vectors with one entry per feature. If not provided, the bounds are computed on the data when .fit() is first called, resulting in a PrivacyLeakWarning.
priors (array-like, shape (n_classes,)) – Prior probabilities of the classes. If specified the priors are not adjusted according to the data.
var_smoothing (float, default: 1e-9) – Portion of the largest variance of all features that is added to variances for calculation stability.
random_state (int or RandomState, optional) – Controls the randomness of the model. To obtain a deterministic behaviour during randomisation, random_state has to be fixed to an integer.
accountant (BudgetAccountant, optional) – Accountant to keep track of privacy budget.

class_prior_

probability of each class.

Type:: array, shape (n_classes,)

class_count_

number of training samples observed in each class.

Type:: array, shape (n_classes,)

theta_

mean of each feature per class

Type:: array, shape (n_classes, n_features)

var_

variance of each feature per class

Type:: array, shape (n_classes, n_features)

epsilon_

absolute additive value to variances (unrelated to epsilon parameter for differential privacy)

Type:: float

References

[VSB13]

Vaidya, Jaideep, Basit Shafiq, Anirban Basu, and Yuan Hong. “Differentially private naive bayes classification.” In 2013 IEEE/WIC/ACM International Joint Conferences on Web Intelligence (WI) and Intelligent Agent Technologies (IAT), vol. 1, pp. 571-576. IEEE, 2013.

fit(X, y, sample_weight=None)[source]

Fit Gaussian Naive Bayes according to X, y.

Parameters:

X (array-like of shape (n_samples, n_features)) – Training vectors, where n_samples is the number of samples and n_features is the number of features.
y (array-like of shape (n_samples,)) – Target values.
sample_weight (array-like of shape (n_samples,), default=None) –
Weights applied to individual samples (1. for unweighted).

New in version 0.17: Gaussian Naive Bayes supports fitting with sample_weight.

Returns:

self – Returns the instance itself.

Return type:

object

get_metadata_routing()

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:: routing – A MetadataRequest encapsulating routing information.
Return type:: MetadataRequest

get_params(deep=True)

Get parameters for this estimator.

Parameters:: deep (bool, default=True) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
Returns:: params – Parameter names mapped to their values.
Return type:: dict

partial_fit(X, y, classes=None, sample_weight=None)[source]

Incremental fit on a batch of samples.

This method is expected to be called several times consecutively on different chunks of a dataset so as to implement out-of-core or online learning.

This is especially useful when the whole dataset is too big to fit in memory at once.

This method has some performance and numerical stability overhead, hence it is better to call partial_fit on chunks of data that are as large as possible (as long as fitting in the memory budget) to hide the overhead.

Parameters:

X (array-like of shape (n_samples, n_features)) – Training vectors, where n_samples is the number of samples and n_features is the number of features.
y (array-like of shape (n_samples,)) – Target values.
classes (array-like of shape (n_classes,), default=None) –
List of all the classes that can possibly appear in the y vector.

Must be provided at the first call to partial_fit, can be omitted in subsequent calls.
sample_weight (array-like of shape (n_samples,), default=None) –
Weights applied to individual samples (1. for unweighted).

New in version 0.17.

Returns:

self – Returns the instance itself.

Return type:

object

predict(X)

Perform classification on an array of test vectors X.

Parameters:: X (array-like of shape (n_samples, n_features)) – The input samples.
Returns:: C – Predicted target values for X.
Return type:: ndarray of shape (n_samples,)

predict_joint_log_proba(X)

Return joint log probability estimates for the test vector X.

For each row x of X and class y, the joint log probability is given by log P(x, y) = log P(y) + log P(x|y), where log P(y) is the class prior probability and log P(x|y) is the class-conditional probability.

Parameters:: X (array-like of shape (n_samples, n_features)) – The input samples.
Returns:: C – Returns the joint log-probability of the samples for each class in the model. The columns correspond to the classes in sorted order, as they appear in the attribute classes_.
Return type:: ndarray of shape (n_samples, n_classes)

predict_log_proba(X)

Return log-probability estimates for the test vector X.

Parameters:: X (array-like of shape (n_samples, n_features)) – The input samples.
Returns:: C – Returns the log-probability of the samples for each class in the model. The columns correspond to the classes in sorted order, as they appear in the attribute classes_.
Return type:: array-like of shape (n_samples, n_classes)

predict_proba(X)

Return probability estimates for the test vector X.

Parameters:: X (array-like of shape (n_samples, n_features)) – The input samples.
Returns:: C – Returns the probability of the samples for each class in the model. The columns correspond to the classes in sorted order, as they appear in the attribute classes_.
Return type:: array-like of shape (n_samples, n_classes)

score(X, y, sample_weight=None)

Return the mean accuracy on the given test data and labels.

In multi-label classification, this is the subset accuracy which is a harsh metric since you require for each sample that each label set be correctly predicted.

Parameters:

X (array-like of shape (n_samples, n_features)) – Test samples.
y (array-like of shape (n_samples,) or (n_samples, n_outputs)) – True labels for X.
sample_weight (array-like of shape (n_samples,), default=None) – Sample weights.

Returns:

score – Mean accuracy of self.predict(X) w.r.t. y.

Return type:

float

set_fit_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → GaussianNB

Request metadata passed to the fit method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 fit.
Returns:: self – The updated object.
Return type:: object

set_params(**params)

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:: **params (dict) – Estimator parameters.
Returns:: self – Estimator instance.
Return type:: estimator instance

set_partial_fit_request(*, classes: bool | None | str = '$UNCHANGED$', sample_weight: bool | None | str = '$UNCHANGED$') → GaussianNB

Request metadata passed to the partial_fit method.

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

The options for each parameter are:

True: metadata is requested, and passed to partial_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 partial_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.

New 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 pipeline.Pipeline. Otherwise it has no effect.

Parameters:

classes (str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED) – Metadata routing for classes parameter in partial_fit.
sample_weight (str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED) – Metadata routing for sample_weight parameter in partial_fit.

Returns:

self – The updated object.

Return type:

object

set_score_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → GaussianNB

Request metadata passed to the score method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 – The updated object.
Return type:: object

property sigma_: Variance of each feature per class.

Logistic Regression

class diffprivlib.models.LogisticRegression(*, epsilon=1.0, data_norm=None, tol=0.0001, C=1.0, fit_intercept=True, max_iter=100, verbose=0, warm_start=False, n_jobs=None, random_state=None, accountant=None, **unused_args)[source]

Logistic Regression (aka logit, MaxEnt) classifier with differential privacy.

This class implements regularised logistic regression using Scipy’s L-BFGS-B algorithm. $\epsilon$-Differential privacy is achieved relative to the maximum norm of the data, as determined by data_norm, by the Vector mechanism, which adds a Laplace-distributed random vector to the objective. Adapted from the work presented in [CMS11].

This class is a child of sklearn.linear_model.LogisticRegression, with amendments to allow for the implementation of differential privacy. Some parameters of Scikit Learn’s model have therefore had to be fixed, including:

The only permitted solver is ‘lbfgs’. Specifying the solver option will result in a warning.

Consequently, the only permitted penalty is ‘l2’. Specifying the penalty option will result in a warning.

In the multiclass case, only the one-vs-rest (OvR) scheme is permitted. Specifying the multi_class option will result in a warning.

Parameters:

epsilon (float, default: 1.0) – Privacy parameter $\epsilon$.
data_norm (float, optional) –
The max l2 norm of any row of the data. This defines the spread of data that will be protected by differential privacy.

If not specified, the max norm is taken from the data when .fit() is first called, but will result in a PrivacyLeakWarning, as it reveals information about the data. To preserve differential privacy fully, data_norm should be selected independently of the data, i.e. with domain knowledge.
tol (float, default: 1e-4) – Tolerance for stopping criteria.
C (float, default: 1.0) – Inverse of regularization strength; must be a positive float. Like in support vector machines, smaller values specify stronger regularization.
fit_intercept (bool, default: True) – Specifies if a constant (a.k.a. bias or intercept) should be added to the decision function.
max_iter (int, default: 100) – Maximum number of iterations taken for the solver to converge. For smaller epsilon (more noise), max_iter may need to be increased.
verbose (int, default: 0) – Set to any positive number for verbosity.
warm_start (bool, default: False) – When set to True, reuse the solution of the previous call to fit as initialization, otherwise, just erase the previous solution.
n_jobs (int, optional) – Number of CPU cores used when parallelising over classes. None means 1 unless in a context. -1 means using all processors.
random_state (int or RandomState, optional) – Controls the randomness of the model. To obtain a deterministic behaviour during randomisation, random_state has to be fixed to an integer.
accountant (BudgetAccountant, optional) – Accountant to keep track of privacy budget.

classes_

A list of class labels known to the classifier.

Type:: array, shape (n_classes, )

coef_

Coefficient of the features in the decision function.

coef_ is of shape (1, n_features) when the given problem is binary.

Type:: array, shape (1, n_features) or (n_classes, n_features)

intercept_

Intercept (a.k.a. bias) added to the decision function.

If fit_intercept is set to False, the intercept is set to zero. intercept_ is of shape (1,) when the given problem is binary.

Type:: array, shape (1,) or (n_classes,)

n_iter_

Actual number of iterations for all classes. If binary, it returns only 1 element.

Type:: array, shape (n_classes,) or (1, )

Examples

>>> from sklearn.datasets import load_iris
>>> from diffprivlib.models import LogisticRegression
>>> X, y = load_iris(return_X_y=True)
>>> clf = LogisticRegression(data_norm=12, epsilon=2).fit(X, y)
>>> clf.predict(X[:2, :])
array([0, 0])
>>> clf.predict_proba(X[:2, :])
array([[7.35362932e-01, 2.16667422e-14, 2.64637068e-01],
       [9.08384378e-01, 3.47767052e-13, 9.16156215e-02]])
>>> clf.score(X, y)
0.5266666666666666

Tree-Based Models

class diffprivlib.models.RandomForestClassifier(n_estimators=10, *, epsilon=1.0, bounds=None, classes=None, n_jobs=1, verbose=0, accountant=None, random_state=None, max_depth=5, warm_start=False, shuffle=False, **unused_args)[source]

Random Forest Classifier with differential privacy.

This class implements Differentially Private Random Decision Forests using [1]. $\epsilon$-Differential privacy is achieved by constructing decision trees via random splitting criterion and applying the PermuteAndFlip Mechanism to determine a noisy label.

Parameters:

n_estimators (int, default: 10) – The number of trees in the forest.
epsilon (float, default: 1.0) – Privacy parameter $\epsilon$.
bounds (tuple, optional) – Bounds of the data, provided as a tuple of the form (min, max). min and max can either be scalars, covering the min/max of the entire data, or vectors with one entry per feature. If not provided, the bounds are computed on the data when .fit() is first called, resulting in a PrivacyLeakWarning.
classes (array-like of shape (n_classes,)) – Array of classes to be trained on. If not provided, the classes will be read from the data when .fit() is first called, resulting in a PrivacyLeakWarning.
n_jobs (int, default: 1) – Number of CPU cores used when parallelising over classes. -1 means using all processors.
verbose (int, default: 0) – Set to any positive number for verbosity.
random_state (int or RandomState, optional) – Controls both the randomness of the shuffling of the samples used when building trees (if shuffle=True) and training of the differentially-private DecisionTreeClassifier to construct the forest. To obtain a deterministic behaviour during randomisation, random_state has to be fixed to an integer.
accountant (BudgetAccountant, optional) – Accountant to keep track of privacy budget.
max_depth (int, default: 5) – The maximum depth of the tree. The depth translates to an exponential increase in memory usage.
warm_start (bool, default=False) – When set to True, reuse the solution of the previous call to fit and add more estimators to the ensemble, otherwise, just fit a whole new forest.
shuffle (bool, default=False) – When set to True, shuffles the datapoints to be trained on trees at random. In diffprivlib, each datapoint is used to train exactly one tree. When set to False, datapoints are chosen in-order to their tree in sequence.

estimator_

The child estimator template used to create the collection of fitted sub-estimators.

Type:: DecisionTreeClassifier

estimators_

The collection of fitted sub-estimators.

Type:: list of DecisionTreeClassifier

classes_

The classes labels.

Type:: ndarray of shape (n_classes,) or a list of such arrays

n_classes_

The number of classes.

Type:: int or list

n_features_in_

Number of features seen during fit.

Type:: int

feature_names_in_

Names of features seen during fit. Defined only when X has feature names that are all strings.

Type:: ndarray of shape (n_features_in_,)

n_outputs_

The number of outputs when fit is performed.

Type:: int

Examples

>>> from sklearn.datasets import make_classification
>>> from diffprivlib.models import RandomForestClassifier
>>> X, y = make_classification(n_samples=1000, n_features=4,
...                            n_informative=2, n_redundant=0,
...                            random_state=0, shuffle=False)
>>> clf = RandomForestClassifier(n_estimators=100, random_state=0)
>>> clf.fit(X, y)
>>> print(clf.predict([[0, 0, 0, 0]]))
[1]

References

[1] Sam Fletcher, Md Zahidul Islam. “Differentially Private Random Decision Forests using Smooth Sensitivity” https://arxiv.org/abs/1606.03572

apply(X)

Apply trees in the forest to X, return leaf indices.

Parameters:: X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, its dtype will be converted to dtype=np.float32. If a sparse matrix is provided, it will be converted into a sparse csr_matrix.
Returns:: X_leaves – For each datapoint x in X and for each tree in the forest, return the index of the leaf x ends up in.
Return type:: ndarray of shape (n_samples, n_estimators)

decision_path(X)

Return the decision path in the forest.

New in version 0.18.

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, its dtype will be converted to dtype=np.float32. If a sparse matrix is provided, it will be converted into a sparse csr_matrix.

Returns:

indicator (sparse matrix of shape (n_samples, n_nodes)) – Return a node indicator matrix where non zero elements indicates that the samples goes through the nodes. The matrix is of CSR format.
n_nodes_ptr (ndarray of shape (n_estimators + 1,)) – The columns from indicator[n_nodes_ptr[i]:n_nodes_ptr[i+1]] gives the indicator value for the i-th estimator.

fit(X, y, sample_weight=None)[source]

Build a forest of trees from the training set (X, y).

Parameters:

X (array-like of shape (n_samples, n_features)) – The training input samples. Internally, its dtype will be converted to dtype=np.float32.
y (array-like of shape (n_samples,)) – The target values (class labels in classification, real numbers in regression).
sample_weight (ignored) – Ignored by diffprivlib. Present for consistency with sklearn API.

Returns:

self – Fitted estimator.

Return type:

object

get_metadata_routing()

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:: routing – A MetadataRequest encapsulating routing information.
Return type:: MetadataRequest

get_params(deep=True)

Get parameters for this estimator.

Parameters:: deep (bool, default=True) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
Returns:: params – Parameter names mapped to their values.
Return type:: dict

predict(X)

Predict class for X.

The predicted class of an input sample is a vote by the trees in the forest, weighted by their probability estimates. That is, the predicted class is the one with highest mean probability estimate across the trees.

Parameters:: X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, its dtype will be converted to dtype=np.float32. If a sparse matrix is provided, it will be converted into a sparse csr_matrix.
Returns:: y – The predicted classes.
Return type:: ndarray of shape (n_samples,) or (n_samples, n_outputs)

predict_log_proba(X)

Predict class log-probabilities for X.

The predicted class log-probabilities of an input sample is computed as the log of the mean predicted class probabilities of the trees in the forest.

Parameters:: X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, its dtype will be converted to dtype=np.float32. If a sparse matrix is provided, it will be converted into a sparse csr_matrix.
Returns:: p – The class probabilities of the input samples. The order of the classes corresponds to that in the attribute classes_.
Return type:: ndarray of shape (n_samples, n_classes), or a list of such arrays

predict_proba(X)

Predict class probabilities for X.

The predicted class probabilities of an input sample are computed as the mean predicted class probabilities of the trees in the forest. The class probability of a single tree is the fraction of samples of the same class in a leaf.

Parameters:: X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, its dtype will be converted to dtype=np.float32. If a sparse matrix is provided, it will be converted into a sparse csr_matrix.
Returns:: p – The class probabilities of the input samples. The order of the classes corresponds to that in the attribute classes_.
Return type:: ndarray of shape (n_samples, n_classes), or a list of such arrays

score(X, y, sample_weight=None)

Return the mean accuracy on the given test data and labels.

In multi-label classification, this is the subset accuracy which is a harsh metric since you require for each sample that each label set be correctly predicted.

Parameters:

X (array-like of shape (n_samples, n_features)) – Test samples.
y (array-like of shape (n_samples,) or (n_samples, n_outputs)) – True labels for X.
sample_weight (array-like of shape (n_samples,), default=None) – Sample weights.

Returns:

score – Mean accuracy of self.predict(X) w.r.t. y.

Return type:

float

set_fit_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → RandomForestClassifier

Request metadata passed to the fit method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 fit.
Returns:: self – The updated object.
Return type:: object

set_params(**params)

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:: **params (dict) – Estimator parameters.
Returns:: self – Estimator instance.
Return type:: estimator instance

set_score_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → RandomForestClassifier

Request metadata passed to the score method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 – The updated object.
Return type:: object

class diffprivlib.models.DecisionTreeClassifier(max_depth=5, *, epsilon=1, bounds=None, classes=None, random_state=None, accountant=None, **unused_args)[source]

Decision Tree Classifier with differential privacy.

This class implements the base differentially private decision tree classifier for the Random Forest classifier algorithm. Not meant to be used separately.

Parameters:

max_depth (int, default: 5) – The maximum depth of the tree.
epsilon (float, default: 1.0) – Privacy parameter $\epsilon$.
bounds (tuple, optional) – Bounds of the data, provided as a tuple of the form (min, max). min and max can either be scalars, covering the min/max of the entire data, or vectors with one entry per feature. If not provided, the bounds are computed on the data when .fit() is first called, resulting in a PrivacyLeakWarning.
classes (array-like of shape (n_classes,), optional) – Array of class labels. If not provided, the classes will be read from the data when .fit() is first called, resulting in a PrivacyLeakWarning.
random_state (int or RandomState, optional) – Controls the randomness of the estimator. At each split, the feature to split on is chosen randomly, as is the threshold at which to split. The classification label at each leaf is then randomised, subject to differential privacy constraints. To obtain a deterministic behaviour during randomisation, random_state has to be fixed to an integer.
accountant (BudgetAccountant, optional) – Accountant to keep track of privacy budget.

n_features_in_

The number of features when fit is performed.

Type:: int

n_classes_

The number of classes.

Type:: int

classes_

The class labels.

Type:: array of shape (n_classes, )

apply(X, check_input=True)

Return the index of the leaf that each sample is predicted as.

New in version 0.17.

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, it will be converted to dtype=np.float32 and if a sparse matrix is provided to a sparse csr_matrix.
check_input (bool, default=True) – Allow to bypass several input checking. Don’t use this parameter unless you know what you’re doing.

Returns:

X_leaves – For each datapoint x in X, return the index of the leaf x ends up in. Leaves are numbered within [0; self.tree_.node_count), possibly with gaps in the numbering.

Return type:

array-like of shape (n_samples,)

decision_path(X, check_input=True)

Return the decision path in the tree.

New in version 0.18.

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, it will be converted to dtype=np.float32 and if a sparse matrix is provided to a sparse csr_matrix.
check_input (bool, default=True) – Allow to bypass several input checking. Don’t use this parameter unless you know what you’re doing.

Returns:

indicator – Return a node indicator CSR matrix where non zero elements indicates that the samples goes through the nodes.

Return type:

sparse matrix of shape (n_samples, n_nodes)

fit(X, y, sample_weight=None, check_input=True)[source]

Build a differentially-private decision tree classifier from the training set (X, y).

Parameters:

X (array-like of shape (n_samples, n_features)) – The training input samples. Internally, it will be converted to dtype=np.float32.
y (array-like of shape (n_samples,)) – The target values (class labels) as integers or strings.
sample_weight (ignored) – Ignored by diffprivlib. Present for consistency with sklearn API.
check_input (bool, default=True) – Allow to bypass several input checking. Don’t use this parameter unless you know what you do.

Returns:

self – Fitted estimator.

Return type:

DecisionTreeClassifier

get_depth()

Return the depth of the decision tree.

The depth of a tree is the maximum distance between the root and any leaf.

Returns:: self.tree_.max_depth – The maximum depth of the tree.
Return type:: int

get_metadata_routing()

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:: routing – A MetadataRequest encapsulating routing information.
Return type:: MetadataRequest

get_n_leaves()

Return the number of leaves of the decision tree.

Returns:: self.tree_.n_leaves – Number of leaves.
Return type:: int

get_params(deep=True)

Get parameters for this estimator.

Parameters:: deep (bool, default=True) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
Returns:: params – Parameter names mapped to their values.
Return type:: dict

predict(X, check_input=True)

Predict class or regression value for X.

For a classification model, the predicted class for each sample in X is returned. For a regression model, the predicted value based on X is returned.

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, it will be converted to dtype=np.float32 and if a sparse matrix is provided to a sparse csr_matrix.
check_input (bool, default=True) – Allow to bypass several input checking. Don’t use this parameter unless you know what you’re doing.

Returns:

y – The predicted classes, or the predict values.

Return type:

array-like of shape (n_samples,) or (n_samples, n_outputs)

predict_log_proba(X)[source]

Predict class log-probabilities of the input samples X.

Parameters:: X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, it will be converted to dtype=np.float32 and if a sparse matrix is provided to a sparse csr_matrix.
Returns:: proba – The class log-probabilities of the input samples. The order of the classes corresponds to that in the attribute classes_.
Return type:: ndarray of shape (n_samples, n_classes) or list of n_outputs such arrays if n_outputs > 1

predict_proba(X, check_input=True)[source]

Predict class probabilities of the input samples X.

The predicted class probability is the fraction of samples of the same class in a leaf.

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – The input samples. Internally, it will be converted to dtype=np.float32 and if a sparse matrix is provided to a sparse csr_matrix.
check_input (bool, default=True) – Allow to bypass several input checking. Don’t use this parameter unless you know what you’re doing.

Returns:

proba – The class probabilities of the input samples. The order of the classes corresponds to that in the attribute classes_.

Return type:

ndarray of shape (n_samples, n_classes) or list of n_outputs such arrays if n_outputs > 1

score(X, y, sample_weight=None)

Return the mean accuracy on the given test data and labels.

In multi-label classification, this is the subset accuracy which is a harsh metric since you require for each sample that each label set be correctly predicted.

Parameters:

X (array-like of shape (n_samples, n_features)) – Test samples.
y (array-like of shape (n_samples,) or (n_samples, n_outputs)) – True labels for X.
sample_weight (array-like of shape (n_samples,), default=None) – Sample weights.

Returns:

score – Mean accuracy of self.predict(X) w.r.t. y.

Return type:

float

set_fit_request(*, check_input: bool | None | str = '$UNCHANGED$', sample_weight: bool | None | str = '$UNCHANGED$') → DecisionTreeClassifier

Request metadata passed to the fit method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 pipeline.Pipeline. Otherwise it has no effect.

Parameters:

check_input (str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED) – Metadata routing for check_input parameter in fit.
sample_weight (str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED) – Metadata routing for sample_weight parameter in fit.

Returns:

self – The updated object.

Return type:

object

set_params(**params)

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:: **params (dict) – Estimator parameters.
Returns:: self – Estimator instance.
Return type:: estimator instance

set_predict_proba_request(*, check_input: bool | None | str = '$UNCHANGED$') → DecisionTreeClassifier

Request metadata passed to the predict_proba method.

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

The options for each parameter are:

True: metadata is requested, and passed to predict_proba 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 predict_proba.
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.

New 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 pipeline.Pipeline. Otherwise it has no effect.

Parameters:: check_input (str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED) – Metadata routing for check_input parameter in predict_proba.
Returns:: self – The updated object.
Return type:: object

set_predict_request(*, check_input: bool | None | str = '$UNCHANGED$') → DecisionTreeClassifier

Request metadata passed to the predict method.

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

The options for each parameter are:

True: metadata is requested, and passed to predict 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 predict.
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.

New 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 pipeline.Pipeline. Otherwise it has no effect.

Parameters:: check_input (str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED) – Metadata routing for check_input parameter in predict.
Returns:: self – The updated object.
Return type:: object

set_score_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → DecisionTreeClassifier

Request metadata passed to the score method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 – The updated object.
Return type:: object

Regression models

Linear Regression

class diffprivlib.models.LinearRegression(*, epsilon=1.0, bounds_X=None, bounds_y=None, fit_intercept=True, copy_X=True, random_state=None, accountant=None, **unused_args)[source]

Ordinary least squares Linear Regression with differential privacy.

LinearRegression fits a linear model with coefficients w = (w1, …, wp) to minimize the residual sum of squares between the observed targets in the dataset, and the targets predicted by the linear approximation. Differential privacy is guaranteed with respect to the training sample.

Differential privacy is achieved by adding noise to the coefficients of the objective function, taking inspiration from [ZZX12].

Parameters:

epsilon (float, default: 1.0) – Privacy parameter $\epsilon$.
bounds_X (tuple) – Bounds of the data, provided as a tuple of the form (min, max). min and max can either be scalars, covering the min/max of the entire data, or vectors with one entry per feature. If not provided, the bounds are computed on the data when .fit() is first called, resulting in a PrivacyLeakWarning.
bounds_y (tuple) – Same as bounds_X, but for the training label set y.
fit_intercept (bool, default: True) – Whether to calculate the intercept for this model. If set to False, no intercept will be used in calculations (i.e. data is expected to be centered).
copy_X (bool, default: True) – If True, X will be copied; else, it may be overwritten.
random_state (int or RandomState, optional) – Controls the randomness of the model. To obtain a deterministic behaviour during randomisation, random_state has to be fixed to an integer.
accountant (BudgetAccountant, optional) – Accountant to keep track of privacy budget.

coef_

Estimated coefficients for the linear regression problem. If multiple targets are passed during the fit (y 2D), this is a 2D array of shape (n_targets, n_features), while if only one target is passed, this is a 1D array of length n_features.

Type:: array of shape (n_features, ) or (n_targets, n_features)

intercept_

Independent term in the linear model. Set to 0.0 if fit_intercept = False.

Type:: float or array of shape of (n_targets,)

References

[ZZX12]

Zhang, Jun, Zhenjie Zhang, Xiaokui Xiao, Yin Yang, and Marianne Winslett. “Functional mechanism: regression analysis under differential privacy.” arXiv preprint arXiv:1208.0219 (2012).

fit(X, y, sample_weight=None)[source]

Fit linear model.

Parameters:

X (array-like or sparse matrix, shape (n_samples, n_features)) – Training data
y (array_like, shape (n_samples, n_targets)) – Target values. Will be cast to X’s dtype if necessary
sample_weight (ignored) – Ignored by diffprivlib. Present for consistency with sklearn API.

Returns:

self

Return type:

returns an instance of self.

get_metadata_routing()

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:: routing – A MetadataRequest encapsulating routing information.
Return type:: MetadataRequest

get_params(deep=True)

Get parameters for this estimator.

Parameters:: deep (bool, default=True) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
Returns:: params – Parameter names mapped to their values.
Return type:: dict

predict(X)

Predict using the linear model.

Parameters:: X (array-like or sparse matrix, shape (n_samples, n_features)) – Samples.
Returns:: C – Returns predicted values.
Return type:: array, shape (n_samples,)

score(X, y, sample_weight=None)

Return the coefficient of determination of the prediction.

The coefficient of determination $R^2$ is defined as $(1 - \frac{u}{v})$, where $u$ is the residual sum of squares ((y_true - y_pred)** 2).sum() and $v$ is the total sum of squares ((y_true - y_true.mean()) ** 2).sum(). The best possible score is 1.0 and it can be negative (because the model can be arbitrarily worse). A constant model that always predicts the expected value of y, disregarding the input features, would get a $R^2$ score of 0.0.

Parameters:

X (array-like of shape (n_samples, n_features)) – Test samples. For some estimators this may be a precomputed kernel matrix or a list of generic objects instead with shape (n_samples, n_samples_fitted), where n_samples_fitted is the number of samples used in the fitting for the estimator.
y (array-like of shape (n_samples,) or (n_samples, n_outputs)) – True values for X.
sample_weight (array-like of shape (n_samples,), default=None) – Sample weights.

Returns:

score – $R^2$ of self.predict(X) w.r.t. y.

Return type:

float

Notes

The $R^2$ score used when calling score on a regressor uses multioutput='uniform_average' from version 0.23 to keep consistent with default value of r2_score(). This influences the score method of all the multioutput regressors (except for MultiOutputRegressor).

set_fit_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → LinearRegression

Request metadata passed to the fit method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 fit.
Returns:: self – The updated object.
Return type:: object

set_params(**params)

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:: **params (dict) – Estimator parameters.
Returns:: self – Estimator instance.
Return type:: estimator instance

set_score_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → LinearRegression

Request metadata passed to the score method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 – The updated object.
Return type:: object

Clustering models

K-Means

class diffprivlib.models.KMeans(n_clusters=8, *, epsilon=1.0, bounds=None, random_state=None, accountant=None, **unused_args)[source]

K-Means clustering with differential privacy.

Implements the DPLloyd approach presented in [SCL16], leveraging the sklearn.cluster.KMeans class for full integration with Scikit Learn.

Parameters:

n_clusters (int, default: 8) – The number of clusters to form as well as the number of centroids to generate.
epsilon (float, default: 1.0) – Privacy parameter $\epsilon$.
bounds (tuple, optional) – Bounds of the data, provided as a tuple of the form (min, max). min and max can either be scalars, covering the min/max of the entire data, or vectors with one entry per feature. If not provided, the bounds are computed on the data when .fit() is first called, resulting in a PrivacyLeakWarning.
random_state (int or RandomState, optional) – Controls the randomness of the model. To obtain a deterministic behaviour during randomisation, random_state has to be fixed to an integer.
accountant (BudgetAccountant, optional) – Accountant to keep track of privacy budget.

cluster_centers_

Coordinates of cluster centers. If the algorithm stops before fully converging, these will not be consistent with labels_.

Type:: array, [n_clusters, n_features]

labels_: Labels of each point

inertia_

Sum of squared distances of samples to their closest cluster center.

Type:: float

n_iter_

Number of iterations run.

Type:: int

References

[SCL16]

Su, Dong, Jianneng Cao, Ninghui Li, Elisa Bertino, and Hongxia Jin. “Differentially private k-means clustering.” In Proceedings of the sixth ACM conference on data and application security and privacy, pp. 26-37. ACM, 2016.

fit(X, y=None, sample_weight=None)[source]

Computes k-means clustering with differential privacy.

Parameters:

X (array-like, shape=(n_samples, n_features)) – Training instances to cluster.
y (Ignored) – not used, present here for API consistency by convention.
sample_weight (ignored) – Ignored by diffprivlib. Present for consistency with sklearn API.

Returns:

self

Return type:

class

fit_predict(X, y=None, sample_weight=None)

Compute cluster centers and predict cluster index for each sample.

Convenience method; equivalent to calling fit(X) followed by predict(X).

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – New data to transform.
y (Ignored) – Not used, present here for API consistency by convention.
sample_weight (array-like of shape (n_samples,), default=None) – The weights for each observation in X. If None, all observations are assigned equal weight.

Returns:

labels – Index of the cluster each sample belongs to.

Return type:

ndarray of shape (n_samples,)

fit_transform(X, y=None, sample_weight=None)

Compute clustering and transform X to cluster-distance space.

Equivalent to fit(X).transform(X), but more efficiently implemented.

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – New data to transform.
y (Ignored) – Not used, present here for API consistency by convention.
sample_weight (array-like of shape (n_samples,), default=None) – The weights for each observation in X. If None, all observations are assigned equal weight.

Returns:

X_new – X transformed in the new space.

Return type:

ndarray of shape (n_samples, n_clusters)

get_feature_names_out(input_features=None)

Get output feature names for transformation.

The feature names out will prefixed by the lowercased class name. For example, if the transformer outputs 3 features, then the feature names out are: [“class_name0”, “class_name1”, “class_name2”].

Parameters:: input_features (array-like of str or None, default=None) – Only used to validate feature names with the names seen in fit().
Returns:: feature_names_out – Transformed feature names.
Return type:: ndarray of str objects

get_metadata_routing()

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:: routing – A MetadataRequest encapsulating routing information.
Return type:: MetadataRequest

get_params(deep=True)

Get parameters for this estimator.

Parameters:: deep (bool, default=True) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
Returns:: params – Parameter names mapped to their values.
Return type:: dict

predict(X, sample_weight='deprecated')

Predict the closest cluster each sample in X belongs to.

In the vector quantization literature, cluster_centers_ is called the code book and each value returned by predict is the index of the closest code in the code book.

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – New data to predict.
sample_weight (array-like of shape (n_samples,), default=None) –
The weights for each observation in X. If None, all observations are assigned equal weight.

Deprecated since version 1.3: The parameter sample_weight is deprecated in version 1.3 and will be removed in 1.5.

Returns:

labels – Index of the cluster each sample belongs to.

Return type:

ndarray of shape (n_samples,)

score(X, y=None, sample_weight=None)

Opposite of the value of X on the K-means objective.

Parameters:

X ({array-like, sparse matrix} of shape (n_samples, n_features)) – New data.
y (Ignored) – Not used, present here for API consistency by convention.
sample_weight (array-like of shape (n_samples,), default=None) – The weights for each observation in X. If None, all observations are assigned equal weight.

Returns:

score – Opposite of the value of X on the K-means objective.

Return type:

float

set_fit_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → KMeans

Request metadata passed to the fit method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 fit.
Returns:: self – The updated object.
Return type:: object

set_output(*, transform=None)

Set output container.

See Introducing the set_output API for an example on how to use the API.

Parameters:

transform ({"default", "pandas"}, default=None) –

Configure output of transform and fit_transform.

”default”: Default output format of a transformer
”pandas”: DataFrame output
None: Transform configuration is unchanged

Returns:

self – Estimator instance.

Return type:

estimator instance

set_params(**params)

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:: **params (dict) – Estimator parameters.
Returns:: self – Estimator instance.
Return type:: estimator instance

set_predict_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → KMeans

Request metadata passed to the predict method.

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

The options for each parameter are:

True: metadata is requested, and passed to predict 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 predict.
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.

New 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 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 predict.
Returns:: self – The updated object.
Return type:: object

set_score_request(*, sample_weight: bool | None | str = '$UNCHANGED$') → KMeans

Request metadata passed to the score method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide 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.

New 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 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 – The updated object.
Return type:: object

transform(X)

Transform X to a cluster-distance space.

In the new space, each dimension is the distance to the cluster centers. Note that even if X is sparse, the array returned by transform will typically be dense.

Parameters:: X ({array-like, sparse matrix} of shape (n_samples, n_features)) – New data to transform.
Returns:: X_new – X transformed in the new space.
Return type:: ndarray of shape (n_samples, n_clusters)

Dimensionality reduction models

PCA

class diffprivlib.models.PCA(n_components=None, *, epsilon=1.0, data_norm=None, centered=False, bounds=None, copy=True, whiten=False, random_state=None, accountant=None, **unused_args)[source]

Principal component analysis (PCA) with differential privacy.

This class is a child of sklearn.decomposition.PCA, with amendments to allow for the implementation of differential privacy as given in [IS16b]. Some parameters of Scikit Learn’s model have therefore had to be fixed, including:

The only permitted svd_solver is ‘full’. Specifying the svd_solver option will result in a warning;

The parameters tol and iterated_power are not applicable (as a consequence of fixing svd_solver = 'full').

Parameters:

n_components (int, float, None or str) –
Number of components to keep. If n_components is not set all components are kept:
```
n_components == min(n_samples, n_features)
```
If n_components == 'mle', Minka’s MLE is used to guess the dimension.

If 0 < n_components < 1, select the number of components such that the amount of variance that needs to be explained is greater than the percentage specified by n_components.

Hence, the None case results in:
```
n_components == min(n_samples, n_features) - 1
```
epsilon (float, default: 1.0) – Privacy parameter $\epsilon$. If centered=False, half of epsilon is used to calculate the differentially private mean to center the data prior to the calculation of principal components.
data_norm (float, optional) –
The max l2 norm of any row of the data. This defines the spread of data that will be protected by differential privacy.

If not specified, the max norm is taken from the data when .fit() is first called, but will result in a PrivacyLeakWarning, as it reveals information about the data. To preserve differential privacy fully, data_norm should be selected independently of the data, i.e. with domain knowledge.
centered (bool, default: False) –
If False, the data will be centered before calculating the principal components. This will be calculated with differential privacy, consuming privacy budget from epsilon.

If True, the data is assumed to have been centered previously (e.g. using StandardScaler), and therefore will not require the consumption of privacy budget to calculate the mean.
bounds (tuple, optional) – Bounds of the data, provided as a tuple of the form (min, max). min and max can either be scalars, covering the min/max of the entire data, or vectors with one entry per feature. If not provided, the bounds are computed on the data when .fit() is first called, resulting in a PrivacyLeakWarning.
copy (bool, default: True) – If False, data passed to fit are overwritten and running fit(X).transform(X) will not yield the expected results, use fit_transform(X) instead.
whiten (bool, default: False) –
When True (False by default) the components_ vectors are multiplied by the square root of n_samples and then divided by the singular values to ensure uncorrelated outputs with unit component-wise variances.

Whitening will remove some information from the transformed signal (the relative variance scales of the components) but can sometime improve the predictive accuracy of the downstream estimators by making their data respect some hard-wired assumptions.
random_state (int or RandomState, optional) – Controls the randomness of the model. To obtain a deterministic behaviour during randomisation, random_state has to be fixed to an integer.
accountant (BudgetAccountant, optional) – Accountant to keep track of privacy budget.

components_

Principal axes in feature space, representing the directions of maximum variance in the data. The components are sorted by explained_variance_.

Type:: array, shape (n_components, n_features)

explained_variance_

The amount of variance explained by each of the selected components.

Equal to n_components largest eigenvalues of the covariance matrix of X.

Type:: array, shape (n_components,)

explained_variance_ratio_

Percentage of variance explained by each of the selected components.

If n_components is not set then all components are stored and the sum of the ratios is equal to 1.0.

Type:: array, shape (n_components,)

singular_values_

The singular values corresponding to each of the selected components. The singular values are equal to the 2-norms of the n_components variables in the lower-dimensional space.

Type:: array, shape (n_components,)

mean_

Per-feature empirical mean, estimated from the training set.

Equal to X.mean(axis=0).

Type:: array, shape (n_features,)

n_components_

The estimated number of components. When n_components is set to ‘mle’ or a number between 0 and 1 (with svd_solver == ‘full’) this number is estimated from input data. Otherwise it equals the parameter n_components, or the lesser value of n_features and n_samples if n_components is None.

Type:: int

n_features_in_

Number of features in the training data.

Type:: int

n_samples_

Number of samples in the training data.

Type:: int

noise_variance_

The estimated noise covariance following the Probabilistic PCA model from Tipping and Bishop 1999. See “Pattern Recognition and Machine Learning” by C. Bishop, 12.2.1 p. 574 or http://www.miketipping.com/papers/met-mppca.pdf. It is required to compute the estimated data covariance and score samples.

Equal to the average of (min(n_features, n_samples) - n_components) smallest eigenvalues of the covariance matrix of X.

Type:: float

Preprocessing

Standard Scaler

class diffprivlib.models.StandardScaler(*, epsilon=1.0, bounds=None, copy=True, with_mean=True, with_std=True, random_state=None, accountant=None)[source]

Standardize features by removing the mean and scaling to unit variance, calculated with differential privacy guarantees. Differential privacy is guaranteed on the learned scaler with respect to the training sample; the transformed output will certainly not satisfy differential privacy.

The standard score of a sample x is calculated as:

z = (x - u) / s

where u is the (differentially private) mean of the training samples or zero if with_mean=False, and s is the (differentially private) standard deviation of the training samples or one if with_std=False.

Centering and scaling happen independently on each feature by computing the relevant statistics on the samples in the training set. Mean and standard deviation are then stored to be used on later data using the transform method.

For further information, users are referred to sklearn.preprocessing.StandardScaler.

Parameters:

epsilon (float, default: 1.0) – The privacy budget to be allocated to learning the mean and variance of the training sample. If with_std=True, the privacy budget is split evenly between mean and variance (the mean must be calculated even when with_mean=False, as it is used in the calculation of the variance.
bounds (tuple, optional) – Bounds of the data, provided as a tuple of the form (min, max). min and max can either be scalars, covering the min/max of the entire data, or vectors with one entry per feature. If not provided, the bounds are computed on the data when .fit() is first called, resulting in a PrivacyLeakWarning.
copy (boolean, default: True) – If False, try to avoid a copy and do inplace scaling instead. This is not guaranteed to always work inplace; e.g. if the data is not a NumPy array, a copy may still be returned.
with_mean (boolean, True by default) – If True, center the data before scaling.
with_std (boolean, True by default) – If True, scale the data to unit variance (or equivalently, unit standard deviation).
random_state (int or RandomState, optional) – Controls the randomness of the model. To obtain a deterministic behaviour during randomisation, random_state has to be fixed to an integer.
accountant (BudgetAccountant, optional) – Accountant to keep track of privacy budget.

scale_

Per feature relative scaling of the data. This is calculated using np.sqrt(var_). Equal to None when with_std=False.

Type:: ndarray or None, shape (n_features,)

mean_

The mean value for each feature in the training set. Equal to None when with_mean=False.

Type:: ndarray or None, shape (n_features,)

var_

The variance for each feature in the training set. Used to compute scale_. Equal to None when with_std=False.

Type:: ndarray or None, shape (n_features,)

n_samples_seen_

The number of samples processed by the estimator for each feature. If there are not missing samples, the n_samples_seen will be an integer, otherwise it will be an array. Will be reset on new calls to fit, but increments across partial_fit calls.

Type:: int or array, shape (n_features,)

diffprivlib.models

Classification models

Gaussian Naive Bayes

Logistic Regression

Tree-Based Models

Regression models

Linear Regression

Clustering models

K-Means

Dimensionality reduction models

PCA

Preprocessing

Standard Scaler

`diffprivlib.models`