knn_voronoi_plot.ipynb

Kernel: Unknown Kernel

import numpy as np
import matplotlib.pyplot as plt

try:
    import probml_utils as pml
except ModuleNotFoundError:
    %pip install -qq git+https://github.com/probml/probml-utils.git
    import probml_utils as pml

from scipy.spatial import KDTree, Voronoi, voronoi_plot_2d

np.random.seed(42)
data = np.random.rand(25, 2)
vor = Voronoi(data)

print("Using scipy.spatial.voronoi_plot_2d, wait...")
voronoi_plot_2d(vor)
xlim = plt.xlim()
ylim = plt.ylim()
pml.savefig("knnVoronoiMesh.pdf")
plt.show()

print("Using scipy.spatial.KDTree, wait a few seconds...")
plt.figure()
tree = KDTree(data)
x = np.linspace(xlim[0], xlim[1], 200)
y = np.linspace(ylim[0], ylim[1], 200)
xx, yy = np.meshgrid(x, y)
xy = np.c_[xx.ravel(), yy.ravel()]
plt.plot(data[:, 0], data[:, 1], "ko")
plt.pcolormesh(x, y, tree.query(xy)[1].reshape(200, 200), cmap="jet")
pml.savefig("knnVoronoiColor.pdf")
plt.show()