Book Image

Julia 1.0 Programming. - Second Edition

By : Ivo Balbaert
Book Image

Julia 1.0 Programming. - Second Edition

By: Ivo Balbaert

Overview of this book

The release of Julia 1.0 is now ready to change the technical world by combining the high productivity and ease of use of Python and R with the lightning-fast speed of C++. Julia 1.0 programming gives you a head start in tackling your numerical and data problems. You will begin by learning how to set up a running Julia platform, before exploring its various built-in types. With the help of practical examples, this book walks you through two important collection types: arrays and matrices. In addition to this, you will be taken through how type conversions and promotions work. In the course of the book, you will be introduced to the homo-iconicity and metaprogramming concepts in Julia. You will understand how Julia provides different ways to interact with an operating system, as well as other languages, and then you'll discover what macros are. Once you have grasped the basics, you’ll study what makes Julia suitable for numerical and scientific computing, and learn about the features provided by Julia. By the end of this book, you will also have learned how to run external programs. This book covers all you need to know about Julia in order to leverage its high speed and efficiency for your applications.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Packt Upsell

Anonymous functions

The function f(x, y)at the end of the Defining functions section can also be written with no name, as an anonymous function:(x, y) -> x^3 - y + x * y. We can, however, bind it to a name, such as f = (x, y) -> x^3 - y + x * y, and then call it, for example, as f(3, 2). Anonymous functions are also often written using the following syntax (note the space before (x)):

  function (x)      x + 2  end(anonymous function)julia> ans(3)5

Often, they are also written with a lambda expression as (x) -> x + 2. Before the stab character (->) are the arguments, and after the stab character we have the return value. This can be shortened to x -> x + 2. A function without arguments would be written as () -> println("hello, Julia").

Here is an anonymous function taking three arguments: (x, y, z) -> 3x + 2y - z. When the performance is important, try to use named functions instead, because calling anonymous functions involves a huge overhead. Anonymous functions are...