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%matplotlib inline

Spectral Clustering Example

This example shows how dask-ml's SpectralClustering scales with the number of samples, compared to scikit-learn's implementation. The dask version uses an approximation to the affinity matrix, which avoids an expensive computation at the cost of some approximation error.



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from sklearn.datasets import make_circles
from sklearn.utils import shuffle
import pandas as pd

from timeit import default_timer as tic
import sklearn.cluster
import dask_ml.cluster
import seaborn as sns

Ns = [2500, 5000, 7500, 10000]
X, y = make_circles(n_samples=10_000, noise=0.05, random_state=0, factor=0.5)
X, y = shuffle(X, y)

timings = []
for n in Ns:
    X, y = make_circles(n_samples=n, random_state=n, noise=0.5, factor=0.5)
    t1 = tic()
    sklearn.cluster.SpectralClustering(n_clusters=2).fit(X)
    timings.append(('Scikit-Learn (exact)', n, tic() - t1))
    t1 = tic()
    dask_ml.cluster.SpectralClustering(n_clusters=2, n_components=100).fit(X)
    timings.append(('dask-ml (approximate)', n, tic() - t1))


df = pd.DataFrame(timings, columns=['method', 'Number of Samples', 'Fit Time'])
sns.factorplot(x='Number of Samples', y='Fit Time', hue='method',
               data=df, aspect=1.5)