Book Image

Mastering Julia - Second Edition

By : Malcolm Sherrington
Book Image

Mastering Julia - Second Edition

By: Malcolm Sherrington

Overview of this book

Julia is a well-constructed programming language which was designed for fast execution speed by using just-in-time LLVM compilation techniques, thus eliminating the classic problem of performing analysis in one language and translating it for performance in a second. This book is a primer on Julia’s approach to a wide variety of topics such as scientific computing, statistics, machine learning, simulation, graphics, and distributed computing. Starting off with a refresher on installing and running Julia on different platforms, you’ll quickly get to grips with the core concepts and delve into a discussion on how to use Julia with various code editors and interactive development environments (IDEs). As you progress, you’ll see how data works through simple statistics and analytics and discover Julia's speed, its real strength, which makes it particularly useful in highly intensive computing tasks. You’ll also and observe how Julia can cooperate with external processes to enhance graphics and data visualization. Finally, you will explore metaprogramming and learn how it adds great power to the language and establish networking and distributed computing with Julia. By the end of this book, you’ll be confident in using Julia as part of your existing skill set.
Table of Contents (14 chapters)

Passing arguments

Most function calls in Julia can involve a set of one or more arguments and, in addition, it is possible to designate an argument as being optional and provide a default value.

It is useful if the number of arguments are of varying length and we may also wish to specify an argument by name rather than by its position in the list.

How this is done will be discussed now.

Default and optional arguments

In the examples so far, all arguments to the function were required, and the function call will produce unless all are provided. If the argument type is not given, a type of Any is passed. It is up to the body or the function to treat an Any argument for all the cases that might occur, or trap the error and raise an exception.

For example, multiplying two integers results in an integer and two reals results in a real. If we multiply an integer by a real, we get a real number. The integer is said to be promoted to a real. Similarly, when a real is multiplied...