make_blobs

sklearn.datasets.make_blobs(n_samples=100, n_features=2, *, centers=None, cluster_std=1.0, center_box=(-10.0, 10.0), shuffle=True, random_state=None, return_centers=False)[source]

Generate isotropic Gaussian blobs for clustering.

Read more in the User Guide.

Parameters:

n_samplesint or array-like, default=100

If int, it is the total number of points equally divided among clusters. If array-like, each element of the sequence indicates the number of samples per cluster.

Changed in version v0.20: one can now pass an array-like to the n_samples parameter

n_featuresint, default=2

The number of features for each sample.

centersint or array-like of shape (n_centers, n_features), default=None

The number of centers to generate, or the fixed center locations. If n_samples is an int and centers is None, 3 centers are generated. If n_samples is array-like, centers must be either None or an array of length equal to the length of n_samples.

cluster_stdfloat or array-like of float, default=1.0

The standard deviation of the clusters.

center_boxtuple of float (min, max), default=(-10.0, 10.0)

The bounding box for each cluster center when centers are generated at random.

shufflebool, default=True

Shuffle the samples.

random_stateint, RandomState instance or None, default=None

Determines random number generation for dataset creation. Pass an int for reproducible output across multiple function calls. See Glossary.

return_centersbool, default=False

If True, then return the centers of each cluster.

Added in version 0.23.

Returns:

Xndarray of shape (n_samples, n_features)

The generated samples.

yndarray of shape (n_samples,)

The integer labels for cluster membership of each sample.

centersndarray of shape (n_centers, n_features)

The centers of each cluster. Only returned if return_centers=True.

See also

make_classification

A more intricate variant.

Examples

>>> from sklearn.datasets import make_blobs
>>> X, y = make_blobs(n_samples=10, centers=3, n_features=2,
...                   random_state=0)
>>> print(X.shape)
(10, 2)
>>> y
array([0, 0, 1, 0, 2, 2, 2, 1, 1, 0])
>>> X, y = make_blobs(n_samples=[3, 3, 4], centers=None, n_features=2,
...                   random_state=0)
>>> print(X.shape)
(10, 2)
>>> y
array([0, 1, 2, 0, 2, 2, 2, 1, 1, 0])

Gallery examples

Release Highlights for scikit-learn 1.1

Release Highlights for scikit-learn 0.23

Probability Calibration for 3-class classification

Probability calibration of classifiers

Normal, Ledoit-Wolf and OAS Linear Discriminant Analysis for classification

A demo of the mean-shift clustering algorithm

An example of K-Means++ initialization

Bisecting K-Means and Regular K-Means Performance Comparison

Compare BIRCH and MiniBatchKMeans

Comparing different clustering algorithms on toy datasets

Comparing different hierarchical linkage methods on toy datasets

Comparison of the K-Means and MiniBatchKMeans clustering algorithms

Demo of DBSCAN clustering algorithm

Demo of HDBSCAN clustering algorithm

Demo of affinity propagation clustering algorithm

Demonstration of k-means assumptions

Inductive Clustering

Selecting the number of clusters with silhouette analysis on KMeans clustering

GMM Initialization Methods

Decision Boundaries of Multinomial and One-vs-Rest Logistic Regression

SGD: Maximum margin separating hyperplane

Comparing anomaly detection algorithms for outlier detection on toy datasets

Demonstrating the different strategies of KBinsDiscretizer

Plot the support vectors in LinearSVC

SVM Tie Breaking Example

SVM: Maximum margin separating hyperplane

SVM: Separating hyperplane for unbalanced classes