Data Science Tutorials in Julia
Learning by doing
This website offers tutorials for MLJ.jl and related packages.
The code included on each tutorial is tested to work reliably under these two conditions:
You are running Julia 1.7.x where "x" is any integer (to check, enter
VERSION
at the REPL).You have activated and instantiated the associated package environment.
To make the tutorial-specific environment available to you, first download (and decompress) the "project folder" that is linked near the top of the tutorial. How you proceed next depends on your chosen mode of interaction:
Pasting code copied from web page directly into the Julia REPL
Recommended for new Julia users.
Activate and instantiate the correct environment by entering this code at the julia>
prompt:
using Pkg; Pkg.activate("Path/To/Project/Folder"); Pkg.instantiate()
You need to replace "Path/To/Project/Folder"
with the actual path to the downloaded project folder. This can be just "."
if Julia has been launched from the command-line, with the project folder as the current directory.
This might take a few minutes for some tutorials, as packages may need to be installed and precompiled.
Running the provided Juptyer notebook
The downloaded project folder contains a Juptyer notebook called tutorial.ipynb
. See the IJulia documentation on how to launch it. Copy and execute the code fragment above in a new notebook cell before evaluating any other cells.
Running the provided Julia script line-by-line from an IDE
In your IDE (e.g., VS Code or emacs) open the file called tutorial.jl
in the downloaded project folder and activate/instantiate by first running the code fragment given above.
Having problems?
Please report issues here. For beginners, the most common issues arise because the Julia version is incorrect, or because of an incorrect package environment. So be sure you have tried the instructions above before raising an issue.
If you need to use an earlier version of Julia, you can try deleting the Manifest.toml
file contained in the project folder and running using Pkg; Pkg.instantiate()
to generate a new package environment, but the exact package versions will be different from those used to test the tutorial and generate the output seen on the tutorial web page.
Elementary data manipulations
If you have some programming experience but are otherwise fairly new to data processing in Julia, you may appreciate the following few tutorials before moving on. In these we provide an introduction to some of the fundamental packages in the Julia data processing universe such as DataFrames, CSV and CategoricalArrays.
How to load data,
Short intro to dataframes,
Dealing with categorical data
Specifying data interpretation
Getting started with MLJ
If you are new to MLJ but are familiar with Julia and with Machine Learning, we recommend you start by going through the short Getting started examples in order:
How to choose a model,
How to fit, predict and transform
How to tune models
How to ensemble models
How to ensemble models (2)
More on ensembles
How to compose models
How to build a learning network
How to create models from learning networks
An extended tutorial on stacking
Additionally, you can refer to the documentation for more detailed information.
Introduction to Statistical Learning with MLJ
This is a sequence of tutorials adapted from the labs associated with An introduction to statistical learning which were originally written in R. These tutorials may be useful if you want a gentle intro to MLJ and other relevant tools in the Julia environment. If you're fairly new to Julia and ML, this is probably where you should start.
Note: the adaptation is fairly liberal, adding content when it helps highlights specificities with MLJ and removing content when it seems unnecessary. Also note that some of the things used in the ISL labs are not (yet) supported by MLJ.
Lab 2, a very short intro to Julia for data analysis
Lab 3, linear regression and metrics
Lab 4, classification with LDA, QDA, KNN and metrics
Lab 5, k-folds cross validation
Lab 6b, Ridge and Lasso regression
Lab 8, Tree-based models
Lab 9, SVM (partial)
Lab 10, PCA and clustering (partial)
End to end examples with MLJ
These are examples that are meant to show how MLJ can be used from loading data to producing a model. They assume familiarity with Machine Learning and MLJ.
Note that these tutorials are not meant to teach you ML or Data Science; there may be better ways to analyse the data, the primary aim is to show quick analysis so that you can get more familiar with using MLJ.
The examples can be followed in any order, the tags can guide you as to which tutorials you may want to look at first.
Telco Churn (MLJ for Data Scientists in Two Hours), intermediate, classification, one-hot, ROC curves, confusion matrices, feature importance, feature selection, controlling iteration, tree booster, hyper-parameter optimization (tuning).
AMES, simple, regression, one-hot, learning network, tuning, deterministic
Wine, simple, classification, standardizer, PCA, knn, multinomial, pipeline
Crabs XGB, simple, classification, xg-boost, tuning
Horse, simple, classification, scientific type and autotype, missing values, imputation, one-hot, tuning
King County Houses, simple, regression, scientific type, tuning, xg-boost
Airfoil, simple, regression, random forest
Boston LGBM, intermediate, regression, LightGBM
Boston Flux, intermediate, regression, Flux, Neural Network
Using GLM.jl, simple, regression
Power Generation, simple, feature pre-processing, regression, temporal data
Breast cancer, simple, model comparisons, binary classification