Introducing Julia

Introduction

Julia is a recent arrival to the world of programming languages, and tutorials and introductory texts are now starting to appear.

The official Julia documentation is pretty good (although it needs more examples!), but it's aimed primarily at the early adopters, developers, and more experienced programmers. Once you've learned the basics of the language, you should refer to it as often as possible.

In addition to the many introductory videos and online Julia blog posts and notebooks, you can purchase (or order) the following Julia tutorials:

• Getting started in Julia Programming, Ivo Balbaert, Packt Publishing

• Mastering Julia, Malcolm Sherrington, Packt Publishing

• Julia in Action, Chris von Csefalvay, Manning Publications

• (in preparation) Learning Julia, Leah Hanson, O'Reilly Publishing

This wikibook (which predates all these publications) is less of a tutorial, and more a collection of notes and examples to help you while you're learning Julia.

The Julia community has established a good ethos of encouraging participation in the development of the language on github. The advantage of this wikibook is that it's made and edited by the Julia community – you can edit anything at any time. If you find something that's wrong, or unclear, feel free to correct it, or add examples. (Your first few edits are reviewed, just in case you have less than good intentions. And, as with the Wikipedia, you should expect your writing to be edited by others!) The focus should be largely on the new user, rather than the computer science expert.

This wikibook has recently been updated to work with the current (as of November 2015) version of Julia, version 0.4.

Outline

Getting started

some introductory words, installation, paths, and various bits of magic

The REPL

Using the REPL; Julia as a calculator; getting help

Arrays and tuples

Storing data – Arrays and tuples; the core of Julia and scientific programming

Types

a quick introduction to types, the way to organize your code and the secret to making your programs fast

Controlling the flow

loops and decisions; ifs and elses

Functions

functions and methods; multiple dispatch

Dictionaries and sets

storing data in dictionaries and sets

Strings and characters

working with strings

Working with text files

reading data from text files; elementary file processing

Working with dates and times

working with date and time functions

Plotting

Plotting; an introduction to some of the plotting packages

Metaprogramming

metaprogramming, expressions and macros

Modules and packages

how Julia code is organized, and should be developed

DataFrames

data frames; organizing data in tables

External links

• custom Google search a custom Google search engine for the Julia language
• The Julia manual - the official rulebook
• Julia Package Listing – a searchable listing of all registered packages
• The Fast Track to julia 0.3 – a Julia cheat sheet
• Compat.jl – for cross-version compatibility (see also: "--depwarn={yes|no|error} [command line] option enables/disables syntax and method deprecation warnings, or turns them into errors" in 0.4)
• Debug.jl – a prototype interactive debugger
• TypeCheck.jl – a type checker for some of the benefits a separate compiled language gives
• Lint.jl – a Lint-tool
• FactCheck.jl – a testing framework
• Writing good Julia functions
• The official "Performance Tips" section
• The official style guide
• John Myles White's style guide
• Composition over inheritance
• Types and inheritance in Julia
• A Month of Julia 30 (or more) blog posts about using Julia