• pg 10: 5th row from the bottom, x^{(i)} \epsilon \mathbb{R}^{150 x 1}, should be x_{j} \epsilon \mathbb{R}^{150 x 1}. (Was correct in the 2nd edition.)

• pg 25: the superscripts (i) in $ \Delta w_{j}=\left(1^{(i)}-(-1)^{(i)}\right) 2^{(i)}=(2) 2^{(i)}=4 $ were initially used for illustration purposes in previous editions but are not necessary and could/should be removed

• pg. 42: It should be "eta=0.01" instead of "eta=0.1" in the sentence

So, let's choose two different learning rates, eta = 0.1 and eta = 0.0001, to start with and plot the cost functions versus the number of epochs to see how well the Adaline implementation learns from the training data.

• pg. 45: Arrows should be perpendicular to the contour lines.

• pg. 56: The comment about the n_iter method can be ignored as it does not apply to recent scikit-learn versions (0.21 and newer)

• pg. 84: It says "XOR gate using the logical_or function from NumPy, " near the bottom, but it should be logical_xor instead of logical_or

• pg. 162. In S_i = \sum_{x in D_i} (x - m_i) (x - m_i)^{\top}, the transpose should be on the first row vector, i.e., S_i = \sum_{x in D_i} (x - m_i)^{\top} (x - m_i).

• pg. 469: Instead of tf.keras.activations.tanh(z) it should be tf.keras.activations.relu(z).

• pg. 524: "valid" and "same" are swapped in the figure here. You can use the 2D version of this figure from the 2nd edition as reference, where this is correct: