Book Image

Julia Programming Projects

By : Adrian Salceanu
Book Image

Julia Programming Projects

By: Adrian Salceanu

Overview of this book

Julia is a new programming language that offers a unique combination of performance and productivity. Its powerful features, friendly syntax, and speed are attracting a growing number of adopters from Python, R, and Matlab, effectively raising the bar for modern general and scientific computing. After six years in the making, Julia has reached version 1.0. Now is the perfect time to learn it, due to its large-scale adoption across a wide range of domains, including fintech, biotech, education, and AI. Beginning with an introduction to the language, Julia Programming Projects goes on to illustrate how to analyze the Iris dataset using DataFrames. You will explore functions and the type system, methods, and multiple dispatch while building a web scraper and a web app. Next, you'll delve into machine learning, where you'll build a books recommender system. You will also see how to apply unsupervised machine learning to perform clustering on the San Francisco business database. After metaprogramming, the final chapters will discuss dates and time, time series analysis, visualization, and forecasting. We'll close with package development, documenting, testing and benchmarking. By the end of the book, you will have gained the practical knowledge to build real-world applications in Julia.
Table of Contents (19 chapters)
Title Page
Copyright and Credits
Dedication
About Packt
Contributors
Preface
Index

Adding support for time zones


As previously mentioned, by default, Julia's date/time objects operate in local time, completely ignoring time zones. However, we can easily extend them to become time-zone aware using the TimeZones package. Please install it in the usual way:

julia> using Pkg
pkg> add TimeZones

Once we inform the compiler that we'll be using TimeZones, a wealth of timezone-related functionalities become available at our fingertips.

We can start by exploring the available time zones:

julia> timezone_names() 
439-element Array{AbstractString,1}: 
 "Africa/Abidjan" 
 "Africa/Accra" 
# output truncated

Let's create a time zone object for Amsterdam:

julia> amstz = TimeZone("Europe/Amsterdam") 
Europe/Amsterdam (UTC+1/UTC+2)

In Julia, a TimeZone is an abstract type that represents information regarding a specific time zone, which means that it can't be instantiated—we can't create objects of this type. Instead, one of its two subtypes will be automatically used—VariableTimeZone...