# Chapter 1 Preface

This book accompanies BGU’s “R” course, at the department of Industrial Engineering and Management. It has several purposes:

• Help me organize and document the course material.
• Help students during class so that they may focus on listening and not writing.
• Help students after class, so that they may self-study.

At its current state it is experimental. It can thus be expected to change from time to time, and include mistakes. I will be enormously grateful to whoever decides to share with me any mistakes found.

I am enormously grateful to Yihui Xie, who’s bookdown R package made it possible to easily write a book which has many mathematical formulae, and R output.

I hope the reader will find this text interesting and useful.

For reproducing my results you will want to run set.seed(1).

## 1.1 Notation Conventions

In this text we use the following conventions: Lower case $$x$$ may be a vector or a scalar, random of fixed, as implied by the context. Upper case $$A$$ will stand for matrices. Equality $$=$$ is an equality, and $$:=$$ is a definition. Norm functions are denoted with $$\Vert x \Vert$$ for vector norms, and $$\Vert A \Vert$$ for matrix norms. The type of norm is indicated in the subscript; e.g. $$\Vert x \Vert_2$$ for the Euclidean ($$l_2$$) norm. Tag, $$x'$$ is a transpose. The distribution of a random vector is $$\sim$$.

## 1.2 Acknowledgements

I have consulted many people during the writing of this text. I would like to thank Yoav Kessler, Lena Novack, Efrat Vilenski, Ron Sarafian, and Liad Shekel in particular, for their valuable inputs.