Basic Example of Kmeans in Python?

To implement Kmeans clustering in Python we can use module - sklearn

Steps of Kmeans

  • Import of libraries
  • Load the Iris dataset
  • Data preprocess
  • Build the Kmeans model
  • Visualize the results

Data

{'data': array([[5.1, 3.5, 1.4, 0.2],
        [4.9, 3. , 1.4, 0.2],
        [4.7, 3.2, 1.3, 0.2],
        [4.6, 3.1, 1.5, 0.2],

Data can be downloaded from seaborn module too:

import seaborn as sns
iris = sns.load_dataset("iris")

data:

sepal_length sepal_width petal_length petal_width species
0 5.1 3.5 1.4 0.2 setosa
1 4.9 3.0 1.4 0.2 setosa
2 4.7 3.2 1.3 0.2 setosa
3 4.6 3.1 1.5 0.2 setosa
4 5.0 3.6 1.4 0.2 setosa

Example

from sklearn.datasets import load_iris
from sklearn.preprocessing import StandardScaler
from sklearn.cluster import KMeans
import matplotlib.pyplot as plt


iris = load_iris()
X = iris.data

scaler = StandardScaler()
X_scaled = scaler.fit_transform(X)

kmeans = KMeans(n_clusters=3, random_state=42)
kmeans.fit(X_scaled)

plt.scatter(X_scaled[:, 0], X_scaled[:, 1], c=kmeans.labels_)
plt.scatter(kmeans.cluster_centers_[:, 0], kmeans.cluster_centers_[:, 1], marker='x', s=200, linewidths=3, color='r')
plt.xlabel('Sepal length (scaled)')
plt.ylabel('Sepal width (scaled)')
plt.show()

Output

Resources

How To create a simple machine learning model in Python?