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

Handling exceptions in Julia

In this recipe, you will discover how to make use of Julia's exception handling mechanism. 

Getting ready

For this recipe, no package installation is required.


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

How to do it...

Sometimes executing code results in an unexpected error. A typical example could be working with a file:

  1. Start the Julia command line and define the following two logger functions that append a log to a file:
functionloglines(filename, lines...)
    f=open(filename, "a")
    foreach(line-> (println(f, line)), lines)
  1. Now, run the functions in the REPL:
julia> loglines("mylog.txt", "Test log:")
ERROR: DomainError with -2.0:
sqrt will only return a complex result if called with a complex argument. Try sqrt(Complex(x)).

Thetry-catchblock makes it possible to suppress the error:

loglines("mylog.txt", "Test log:")