hinge_loss_plot.ipynb

Kernel: Unknown Kernel

# Plots 0-1, hinge and log loss.


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

zeroOne = np.vectorize(lambda x: 1 * (x <= 0))
hinge = np.vectorize(lambda x: max(0, 1 - x))
logLoss = np.vectorize(lambda x: np.log2(1 + np.exp(-x)))
expLoss = np.vectorize(lambda x: np.exp(-x))

funs = [zeroOne, hinge, logLoss, expLoss]
styles = ["k-", "b:", "r-.", "g-"]
labels = ["0-1 loss", "hinge loss", "log loss", "exp loss"]
x = np.arange(-2, 2, 0.01)

for i, fun in enumerate(funs):
    plt.plot(x, fun(x), styles[i], label=labels[i], linewidth=2)

plt.axis([-2.1, 2.1, -0.1, 3.1])
plt.legend(fontsize=12)
pml.savefig("hingeLoss.pdf")
plt.show()