Random Forest models can be difficult to interpret, and Bellatrex addresses this challenge by generating explanations that are easy to understand, and by providing insights into how the model arrived at its predictions. Bellatrex does so by Building Explanations through a LocalLy AccuraTe Rule EXtractor (hence the name: Bellatrex) for a given test instance, by extracting only a few, diverse rules. See the published paper for more details.
To illustrate how Bellatrex works, let's consider an example: when a user provides a test instance to Bellatrex, the tool begins by 1) pre-selecting a subset of the rules used to make the prediction; it then creates 2) a vector representation of such rules and 3) projects them to a low-dimensional space; Bellatrex then 4) clusters such representations to pick a rule from each cluster to explain the instance prediction. One rule per cluster is shown to the end user through visually appealing plots, and the tool's GUI allows users to explore similar rules to those extracted.
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| Overview representation of Bellatrex, starting from top left, proceeding clockwise, we reach the output and explanation on the bottom left. |
Another strength of Bellatrex lies in its ability to handle several prediction tasks within scikit-learn implementations of Random Forests. For instance, Bellatrex can generate explanations for binary classification and multi-label predictions tasks with RandomForestClassifier, as well as single- or multi-output regression tasks with RandomForestRegressor. Moreover, Bellatrex is compatible with scikit-survival's RandomSurvivalForest, allowing it to generate explanations for time-to-event predictions in the presence of right-censored data.
This repository contains:
- instructions to run Bellatrex on your machine
- an overwview of the datasets used to test the effectiveness of the method
- accesss to such datasets, as they appear after the pre-processing step.
To ensure that Bellatrex runs correctly, use a Python environment that matches the requirements indicated in requirements.txt. To minimize the chances of encountering compatibility issues, we advice to install the packages on a new (conda) environment with Anaconda:
conda create --name bellatrex-tutorial python=3.10
activate the environment and proceed by installing the packages listed in the requirements.txt file, namely:
conda install scikit-learn==1.2.2
conda install scikit-survival==0.21.0
conda install matplotlib==3.8.0
The scikit-survival package allows to run time-to-event predictions with RandomSurvivalForest.
In case of errors it can also be installed by executing the command conda install -c sebp scikit-survival=0.21.
Install the Orange library with conda install orange3==3.30 to replicate the statistical tests reported in the manuscript.
For an enhanced user experience that includes interactive plots, install the following packages through pip (not available on Anaconda):
pip install dearpygui==1.6.2
pip install dearpygui-ext==0.9.5
To then make use of the Graphical User Interface, set the variable SET_PLOT_GUI equal toTrue to change the value of the plot_GUI attribute on a Bellatrex instance.
Note: When running Bellatrex with the GUI for multiple test samples, the program will generate an interactive window. The process may take a couple of seconds, and the the user has to click at least once within the generated window in order to activate the interactive mode. Once this is done, the user can explore the generated rules by clicking on the corresponding representation. To show the Bellatrex explanation for the next sample, close the interactive window and wait until Bellatrex generates the explanation for the new sample.
If you have downloaded the content of this folder and installed the packages successfully, you can dive into the tutorial.ipynb code and try Bellatrex yourself!