Book Image

Mastering Julia - Second Edition

By : Malcolm Sherrington
Book Image

Mastering Julia - Second Edition

By: Malcolm Sherrington

Overview of this book

Julia is a well-constructed programming language which was designed for fast execution speed by using just-in-time LLVM compilation techniques, thus eliminating the classic problem of performing analysis in one language and translating it for performance in a second. This book is a primer on Julia’s approach to a wide variety of topics such as scientific computing, statistics, machine learning, simulation, graphics, and distributed computing. Starting off with a refresher on installing and running Julia on different platforms, you’ll quickly get to grips with the core concepts and delve into a discussion on how to use Julia with various code editors and interactive development environments (IDEs). As you progress, you’ll see how data works through simple statistics and analytics and discover Julia's speed, its real strength, which makes it particularly useful in highly intensive computing tasks. You’ll also and observe how Julia can cooperate with external processes to enhance graphics and data visualization. Finally, you will explore metaprogramming and learn how it adds great power to the language and establish networking and distributed computing with Julia. By the end of this book, you’ll be confident in using Julia as part of your existing skill set.
Table of Contents (14 chapters)

Text files

When dealing with files on disk, they need to be opened. The process establishes a channel to the file that may be for reading, writing, or both.

How this is done depends on the arguments to the open() call and there are two main (equivalent) syntaxes:

open(filename::AbstractString; keywords...)
open(filename::AbstractString, [mode::AbstractString]

The difference is largely historical and inherent in the forms of operating system shell commands.

The keywords consist of a set of five Boolean arguments:

  • Read open for read, not write
  • Write open for write, truncate, or append
  • Create if does not exist; not read and write or truncate or append
  • Truncate to zero-size; not read and write
  • Append seek to end of file false

Not all of the combinations of the flags are logically consistent, so it is more usual to employ the other form where the mode is passed as an ASCII string:

  • r: Read
  • w: Write, create, truncate
  • a: Write, create...