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
About Packt

Working with date and time accessors

If we want to access the individual parts of a date (year, month, day), we can retrieve the various components through the available accessor functions:

julia> earth_day = Date(2018, 4, 22) 

julia>year(earth_day) # the year 

julia> month(earth_day) # the month  

The API also exposes compound methods, for brevity:

julia> monthday(earth_day) # month and day 
(4, 22) 

julia> yearmonthday(earth_day) # year month and day 
(2018, 4, 22)

Similar accessors are available for DateTime—but no compound methods are provided:

julia> earth_hour = DateTime(2018, 4, 22, 22, 00) 

julia> hour(earth_hour) # the hour 

julia> minute(earth_hour) # the minute 

Alternative accessors that return Period objects are also defined—they have uppercase names:

julia> Hour(earth_hour) # a period of 22 hours 
22 hours 

julia> Month(earth_hour) # a period of 4 months 
4 months 
julia> Month(earth_hour) |&gt...