The first step to understanding anything is to measure it. The same goes for writing high-performance Julia code. We need to measure the performance of the code as the first step to achieving that. As a high-performance language, Julia includes many tools to do this easily, effectively, and accurately. Many of these are built into the language and the standard library, while others are in external packages that can be installed with a single command. All of these tools not only make it easy to measure the performance of the code; they also make it easy to execute the measurement correctly.
When reading this book, whether in print or on screen, we encourage you to run the code and see the results for yourself. The concepts in this book will become much easier to learn if you run the code yourself. The simplest would be to copy/paste the code you see...