Book Image

Julia 1.0 Programming Cookbook

By : Bogumił Kamiński, Przemysław Szufel
Book Image

Julia 1.0 Programming Cookbook

By: Bogumił Kamiński, Przemysław Szufel

Overview of this book

Julia, with its dynamic nature and high-performance, provides comparatively minimal time for the development of computational models with easy-to-maintain computational code. This book will be your solution-based guide as it will take you through different programming aspects with Julia. Starting with the new features of Julia 1.0, each recipe addresses a specific problem, providing a solution and explaining how it works. You will work with the powerful Julia tools and data structures along with the most popular Julia packages. You will learn to create vectors, handle variables, and work with functions. You will be introduced to various recipes for numerical computing, distributed computing, and achieving high performance. You will see how to optimize data science programs with parallel computing and memory allocation. We will look into more advanced concepts such as metaprogramming and functional programming. Finally, you will learn how to tackle issues while working with databases and data processing, and will learn about on data science problems, data modeling, data analysis, data manipulation, parallel processing, and cloud computing with Julia. By the end of the book, you will have acquired the skills to work more effectively with your data
Table of Contents (18 chapters)
Title Page
Copyright and Credits
About Packt

Creating a function preimage - understanding how dictionaries and sets work

In this recipe, we will explain in detail how the Dict and Set types identify keys in Julia.

Getting ready

The example that we will use is the creation of a dictionary that stores a preimage function.

Given a function, 


, we will call preimage of 

 a set 

; see the example at

In particular, we need to create preimage of all possible values of a mapping, 

, given the domain,

 and the set B defined as an image of A under 

, as calculated by Julia.


In the GitHub repository for this recipe, you will find the commands.txt file that contains the presented sequence of shell and Julia commands.

Now open your favorite terminal to execute commands.

How to do it...

We will perform the computations in three steps. Firstly, we create an appropriate data structure that will hold our data, then we will add elements to it, and finally, we will print out its contents to understand which key...