Book Image

Learning Julia

By : Anshul Joshi, Rahul Lakhanpal
Book Image

Learning Julia

By: Anshul Joshi, Rahul Lakhanpal

Overview of this book

Julia is a highly appropriate language for scientific computing, but it comes with all the required capabilities of a general-purpose language. It allows us to achieve C/Fortran-like performance while maintaining the concise syntax of a scripting language such as Python. It is perfect for building high-performance and concurrent applications. From the basics of its syntax to learning built-in object types, this book covers it all. This book shows you how to write effective functions, reduce code redundancies, and improve code reuse. It will be helpful for new programmers who are starting out with Julia to explore its wide and ever-growing package ecosystem and also for experienced developers/statisticians/data scientists who want to add Julia to their skill-set. The book presents the fundamentals of programming in Julia and in-depth informative examples, using a step-by-step approach. You will be taken through concepts and examples such as doing simple mathematical operations, creating loops, metaprogramming, functions, collections, multiple dispatch, and so on. By the end of the book, you will be able to apply your skills in Julia to create and explore applications of any domain.
Table of Contents (17 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
8
Data Visualization and Graphics

User-defined and composite data types


Until now, we have been dealing with the data types that were available to a user and provided by Julia. Now we will be exploring ways to use types that are not made available to us by Julia, and we need to create them in order to address the problems we are dealing or intend to deal with.

The most important keyword that we need to create a user-defined data type is called an type. The following is an example of how to create a simple data type in Julia:

julia> type Person
                  name::String
                  age::Int64
              end

julia> rahul = Person("rahul",27)
Person("rahul",27)

julia> typeof(rahul)
Person

julia> rahul.name
"rahul"

julia> rahul.age
27

This example is one of the simplest examples of what we can consider a user-defined type in Julia. Observing closely, the Person type has two fields, namely name and age. The fields can easily be accessed by using a period (.) notation.

Interestingly, if you try to...