DBSCAN Clustering

Preliminaries

# Load libraries
from sklearn import datasets
from sklearn.preprocessing import StandardScaler
from sklearn.cluster import DBSCAN

# Load data
X = iris.data

Standardize Features

# Standarize features
scaler = StandardScaler()
X_std = scaler.fit_transform(X)

Conduct Meanshift Clustering

DBSCAN has three main parameters to set:

• eps: The maximum distance from an observation for another observation to be considered its neighbor.
• min_samples: The minimum number of observation less than eps distance from an observation for to be considered a core observation.
• metric: The distance metric used by eps. For example, minkowski, euclidean, etc. (note that if Minkowski distance is used, the parameter p can be used to set the power of the Minkowski metric)

If we look at the clusters in our training data we can see two clusters have been identified, 0 and 1, while outlier observations are labeled -1.

# Create meanshift object
clt = DBSCAN(n_jobs=-1)

# Train model
model = clt.fit(X_std)