Intro

The Julia language is a modern language; the website https://julialang.org/ gives a short overview of Julia:

While Python was

  1. never intended to work with matrices of numbers (ironically, it is the number one language to handle exactly that...)
  2. can be considered mainly a frontend for C or C++ code
  3. has a lot of design flaws that need to be "fixed" by numerous packages
  4. has a community that never decides on a single way to do things,

Julia was designed from the ground up to be a high-performance language for technical computing. In short, this means you wont need:

  • pip, venv, pyenv, conda, pdm, poetry or rye to manage your environments
  • numpy to handle arrays fast (Julia is actually designed to handle numbers)
  • pydantic to handle data validation
  • any package that has a C or C++ backend; anything is written in Julia!
  • get packages like DataFrames, which is about 10x as fast as pandas

1. Fast (and energy efficient)

Julia was designed for high performance. Julia programs automatically compile to efficient native code via LLVM, and support multiple platforms. Try to spot python and julia in the graph below.

This also translates to energy efficiency; when taking C as the benchmark, Julia scores 1.8, while Python is among one of the least efficient languages with a score of 75.88. (full benchmarks, see here)

Considering we will be teaching students, let's estimate they will be programming between 4 (2^2) and 32 (2^5) hours a week, a reasonable estimate would be that on average they will program 2^3.5 = 11 hours a week. This is a significant amount of programming that will be done every year by our students (11 hours *42 weeks * 30 students = 14000 hours per year for the next 10-30 consecutive years for every class we teach). Reducing energy-efficiency by a factor of almost 40 will have a significant impact on the environment.

2. Reproducible environments

Julia handles environments quite different, compared to what you might be used to in Python.

Every dependency is installed into a single, central location. Once. Contrast this to Python where every environment has it's own copy of the same package...

3. General purpose

Julia provides asynchronous I/O, metaprogramming, debugging, logging, profiling, a package manager, and more. One can build entire Applications and Microservices in Julia.

Machine learning ecosystem

Most important, from the perspective as a datascientist: Julia is developped by MIT, and adopted by a lot of universities. The ecosystem for data science is broad and very solid. Consider that Julia is being used by NASA and the Brazilian INPE for space missions.

The development of programming languages has come a long way since the development of Python. But some languages (eg, Rust) just don't have an ecosystem for datascience and machinelearning. Because you dont want to invent the wheel over and over again, you do need a scientific community that builds pacakges on top of the base language.

4. Dynamically typed and Composable

Julia is dynamically typed, feels like a scripting language, and has good support for interactive use, so it's both usefull for rapid prototyping and building solid, typed code.

Julia uses multiple dispatch as a paradigm, making it easy to express many object-oriented and functional programming patterns. The talk on the Unreasonable Effectiveness of Multiple Dispatch explains why it works so well, but we will dive into what this is, how it works and when it is usefull during this crash course.

Read more

  1. installation
  2. REPL
  3. Puzzle