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## You selected

### Python Machine Learning

#### Sebastian Raschka

#### Published 2015-09-23

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## Errata

- 24 submitted: last submission 20 Sep 2018**Chapter 2, Training Machine Learning Algorithms for Classification | Section: Training a perceptron model on the Iris dataset | Page no: 28**

One-vs.-All (OvA), or sometimes also called One-vs.-Rest (OvR), is a technique, us to extend a binary classifier to multi-class problems.

Should be:

One-vs.-All (OvA), or sometimes also called One-vs.-Rest (OvR), is a technique, **used** to extend a binary classifier to multi-class problems.

**Chapter 1, Giving Computers the Ability to Learn from Data | Section: Solving interactive problems with reinforcement learning | Page no: 6**

The labells "Action" and "State" have been swapped in the diagram.

**Chapter 1, Giving Computers the Ability to Learn from Data | Section: An introduction to the basic terminology and notations | Page no: 8**

The Iris dataset contains the measurements of 150 iris flowers from three different species: Setosa, Versicolor, and **Viriginica**.

Should be :

The Iris dataset contains the measurements of 150 iris flowers from three different species: Setosa, Versicolor, and **Virginica**.

**Chapter 1, Giving Computers the Ability to Learn from Data | Section: An introduction to the basic terminology and notations | Page no: 10**

Thus, each row in this feature matrix represents one flower instance and can be written as four-dimensional **column** vector

Should be:

Thus, each row in this feature matrix represents one flower instance and can be written as four-dimensional **row** vector

And

Each feature dimension is a 150-dimensional **row** vector

Should be:

Each feature dimension is a 150-dimensional **column** vector

Errata Type: Support Query | Access to code bundle and other data sets |

The datasets to GitHub, the reader can find the datasets at **https://github.com/rasbt/python-machine-learning-book/tree/master/code/datasets**

The direct link to the Iris dataset would be: **https://raw.githubusercontent.com/rasbt/python-machine-learning-book/master/code/datasets/iris/iris.data**

We've added some additional notes to the code notebooks mentioning the offline datasets in case there are server errors. **https://www.dropbox.com/sh/tq2qdh0oqfgsktq/AADIt7esnbiWLOQODn5q_7Dta?dl=0**

Errata Type: **Typo** l Page No. **116 **

This: Since we **the** fit the LogisticRegression object on a multiclass dataset, it uses the

Should be: Since we fit the LogisticRegression object on a multiclass dataset, it uses the

Errata Type: **Typo** l Page No. **128**

This: In a nutshell, PCA aims to find the directions of maximum variance in high-dimensional data and projects it onto a new subspace with equal or fewer dimensions **that** the original one.

Should be: In a nutshell,PCA aims to find the directions of maximum variance in high-dimensional data and projects it onto a new subspace with equal or fewer dimensions **than** the original one.

**Errata Type: Code, Page number 205.**

**It is:**

p(i_1 | x)=0.2x0.1 + 0.2x0.2 + 0.6x0.**06**

**Should be:**

p(i_1 | x)=0.2x0.1 + 0.2x0.2 + 0.6x0.**6**

**Errata Type: Grammar | Chapter 11 | Page 313**

**It is: '**Thus, our goal is to group the samples based on their feature similarities, which **we** can be achieved using the k-means algorithm...'

**Should be: '**Thus, our goal is to group the samples based on their feature similarities, which can be achieved using the k-means algorithm...'

**Errata Type: Code | Chapter 10 | Page 298**

**It is: ** y=w^{0} + w_{1}x + w_{2}x^{2}** x ^{2}**+…+w

_{d}x

^{d}

**Should be: ** y=w^{0} + w_{1}x + w_{2}x^{2}+…+w_{d}x^{d}

**Errata Type: Code| Chapter 10 | Page 305**

**It is: **>>> sort_idx = X.flatten().argsort()

>>> lin_regplot(X[sort_idx], y[sort_idx], tree)

**Should be:** >>> sort_idx = X.flatten().argsort() lin_regplot(X[sort_idx], y[sort_idx], tree)

On page no: 19

The term "unit step function” is not entirely correct here since the class labels are {1, -1} and not {1, 0}. The best term to use would be just be “piecewise-defined function” in this case.

Page 28: If the link 'https://archive.ics.uci.edu/ml/machine-learning-databases/iris/iris.data' doesn't work/open then please try below link

https://raw.githubusercontent.com/rasbt/python-machine-learning-book/master/code/datasets/iris/iris.data

**Errata Type: Grammar, Page number 133 PDF:**

**It is:**

for i inrange(len(eigen_vals))]

**Should be:**

for i in range(len(eigen_vals))]

**Errata Type: Grammar, Page number 142 PDF:**

**It is:**

S_B += n * (mean_vec - mean_overall).dot(

**Should be:**

...S_B += n * (mean_vec - mean_overall).dot(

**Errata Type: Grammar, Page number 145 PDF:**

**It is:**

plt.scatter(X_train_lda[y_train==l, 0]*(-1)

... X_train_lda[y_train==l, 1]*(-1)

**Should be:**

plt.scatter(X_train_lda[y_train==l, 0]*(-1),

... X_train_lda[y_train==l, 1]*(-1),

**Errata Type : Typo | Page No. 289**

This: "plt.show**()w**"

Should be: " plt.show**()**"

Errata Type : Typo | Page No. 51

**This:**

Later in Chapter 5, Compressing Data via Dimensionality Reduction,

we will discuss the best practices around model evaluation in more detail

**Should be:**

Later in Chapter 6, Learning Best Practices for Model

Evaluation and Hyperparameter Tuning

Errata Type: Code | Page 241

This:

text = re.sub('[\W]+', ' ', text.lower()) + \

'.join(emoticons).replace('-', '')

Should be:

text = re.sub('[\W]+', ' ', text.lower()) + \

''.join(emoticons).replace('-', '')

Errata type: Grammar l Page no: 43

This:data can be discarded after updating the model if storage space **in** an issue

Should be: data can be discarded after updating the model if storage space **is** an issue

**Errata Typo: Chapter 3 Page 72 **

This: We can then we use the parameter C to control the width of the margin and therefore tune the bias-variance trade-off as illustrated in the

following figure

Should be: We can then use the parameter C to control the width of the margin and therefore tune the bias-variance trade-off as illustrated in the

following figure

**Errata Type : Graphics| Page : 147**

The 2 figures should be swapped round. The top figure is actually for the test data. The bottom figure is actually for the training data.

**Errata Type: Code | Chapter: 7 | Page: 229**

It is: max_depth=None,

Should be: max_depth=1,

**Errata type: Typo | Page number: 378**

This:

Assuming that we named our modified ~ a new MLP with 10 hidden **layers**.

Should be:

Assuming that we named our modified ~ a new MLP with 10 hidden **units.**

**Errata Type: Technical|Page Number: 58**

It is:

**phi(z)=0.5**

Should be:

** phi(0) = 0.5**

**Errata Type: Typo | Page 116**

Current content :

The first sentence of the third prose block of text reads:

"Since we the fit the LogisticRegression object"

It should be:

"Since we fit the LogisticRegression object"