Book Image

Julia 1.0 Programming Complete Reference Guide

By : Ivo Balbaert, Adrian Salceanu
Book Image

Julia 1.0 Programming Complete Reference Guide

By: Ivo Balbaert, Adrian Salceanu

Overview of this book

Julia offers the high productivity and ease of use of Python and R with the lightning-fast speed of C++. There’s never been a better time to learn this language, thanks to its large-scale adoption across a wide range of domains, including fintech, biotech and artificial intelligence (AI). You will begin by learning how to set up a running Julia platform, before exploring its various built-in types. This Learning Path walks you through two important collection types: arrays and matrices. You’ll be taken through how type conversions and promotions work, and in further chapters you'll study how Julia interacts with operating systems and other languages. You’ll also learn about the use of macros, what makes Julia suitable for numerical and scientific computing, and how to run external programs. Once you have grasped the basics, this Learning Path goes on to how to analyze the Iris dataset using DataFrames. While building a web scraper and a web app, you’ll explore the use of functions, methods, and multiple dispatches. In the final chapters, you'll delve into machine learning, where you'll build a book recommender system. By the end of this Learning Path, you’ll be well versed with Julia and have the skills you need to leverage its high speed and efficiency for your applications. This Learning Path includes content from the following Packt products: • Julia 1.0 Programming - Second Edition by Ivo Balbaert • Julia Programming Projects by Adrian Salceanu
Table of Contents (18 chapters)

Exception handling

When executing a program, abnormal conditions can occur that force the Julia runtime to throw an exception or error, show the exception message and the line where it occurred, and then exit. For example (follow along with the code in Chapter 4\errors.jl):

  • Using the wrong index for an array, for example, arr = [1,2,3]and then asking for arr[0] causes a program to stop with ERROR: BoundsError()
  • Calling sqrt() on a negative value, for example, sqrt(-3) causes ERROR: DomainError: sqrt will only return a complex result if called with a complex argument, try sqrt(complex(x)); the sqrt(complex(-3)) function gives the correct result 0.0 + 1.7320508075688772im
  • A syntax error in Julia code will usually result in LoadError

Similar to these, there are 18 predefined exceptions that Julia can generate (refer to http://docs.julialang.org/en/latest/manual/control-flow/#man...