A continual learning survey: Defying forgetting in classification tasks

This is the original source code for the Continual Learning survey paper "A continual learning survey: Defying forgetting in classification tasks" published at TPAMI [TPAMI paper] [Open-Access paper].

This work allows comparing the state-of-the-art in a fair fashion using the Continual Hyperparameter Framework, which sets the hyperparameters dynamically based on the stability-plasticity dilemma. This addresses the longstanding problem in literature to set hyperparameters for different methods in a fair fashion, using ONLY the current task data (hence without using iid validation data, which is not available in continual learning).

The code contains a generalizing framework for 11 SOTA methods and 4 baselines in Pytorch. </br> Implemented task-incremental methods are

<div align="center"> <p align="center"><b> SI | EWC | MAS | mean/mode-IMM | LWF | EBLL | PackNet | HAT | GEM | iCaRL </b></p> </div>

These are compared with 4 baselines:

<div align="center"> <p align="center"><b> Joint | Finetuning | Finetuning-FM | Finetuning-PM </b></p> </div>

• Joint: Learn from all task data at once with a single head (multi-task learning baseline).
• Finetuning: standard SGD
• Finetuning with Full Memory replay: Allocate memory dynamically to incoming tasks.
• Finetuning with Partial Memory replay: Divide memory a priori over all tasks.

This source code is released under a Attribution-NonCommercial 4.0 International license, find out more about it in the LICENSE file.

Pipeline

Reproducibility: Results from the paper can be obtained from src/main_'dataset'.sh. Full pipeline example in src/main_tinyimagenet.sh .

Pipeline: Constructing a custom pipeline typically requires the following steps.

1. Project Setup
   1. For all requirements see requirements.txt. Main packages can be installed as in

      conda create --name <ENV-NAME> python=3.7
      conda activate <ENV-NAME>
      
      # Main packages
      conda install -c conda-forge matplotlib tqdm
      conda install pytorch torchvision cudatoolkit=10.2 -c pytorch
      
      # For GEM QP
      conda install -c omnia quadprog
      
      # For PackNet: torchnet 
      pip install git+https://github.com/pytorch/tnt.git@master
      

   2. Set paths in 'config.init' (or leave default)
      1. '{tr,test}_results_root_path': where to save training/testing results.
      2. 'models_root_path': where to store initial models (to ensure same initial model)
      3. 'ds_root_path': root path of your datasets
   3. Prepare dataset: see src/data/"dataset"_dataprep.py (e.g. src/data/tinyimgnet_dataprep.py)
2. Train any out of the 11 SOTA methods or 4 baselines
   1. Regularization-based/replay methods: We run a first task model dump, for Synaptic Intelligence (SI) as it acquires importance weights during training. Other methods start from this same initial model.
   2. Baselines/parameter isolation methods: Start training sequence from scratch
3. Evaluate performance, sequence for testing on a task is saved in dictionary format under test_results_root_path defined in config.init.
4. Plot the evaluation results, using one of the configuration files in utilities/plot_configs

Implement Your Method

1. Find class "YourMethod" in methods/method.py. Implement the framework phases (documented in code).
2. Implement your task-based training script in methods: methods/"YourMethodDir". The class "YourMethod" will call this code for training/eval/processing of a single task.

Project structure

• src/data: datasets and automated preparation scripts for Tiny Imagenet and iNaturalist.
• src/framework: the novel task incremental continual learning framework. main.py starts training pipeline, specify --test argument to perform evaluation with eval.py.
• src/methods: all methods source code and method.py wrapper.
• src/models: net.py all model preprocessing.
• src/utilities: utils used across all modules and plotting.
• Config:
  • src/data/{datasets/models}: default datasets and models directory (see config.init)
  • src/results/{train/test}: default training and testing results directory (see config.init)

Credits

• Consider citing our work upon using this repo.

  @ARTICLE{delange2021clsurvey,
    author={M. {Delange} and R. {Aljundi} and M. {Masana} and S. {Parisot} and X. {Jia} and A. {Leonardis} and G. {Slabaugh} and T. {Tuytelaars}},
    journal={IEEE Transactions on Pattern Analysis and Machine Intelligence}, 
    title={A continual learning survey: Defying forgetting in classification tasks}, 
    year={2021},volume={},number={},pages={1-1},
    doi={10.1109/TPAMI.2021.3057446}}
  

• Thanks to Huawei for funding this project.
• Checkout the CL Avalanche project for benchmark setups of TinyImagenet and iNaturalist2018.
• Thanks to the following repositories:
  • https://github.com/rahafaljundi/MAS-Memory-Aware-Synapses
  • https://github.com/facebookresearch/GradientEpisodicMemory
  • https://github.com/arunmallya/packnet
  • https://github.com/joansj/hat

• If you want to join the Continual Learning community, checkout https://www.continualai.org

Support

• If you have troubles, please open a Git issue.
• Have you defined your method in the framework and want to share it with the community? Send a pull request!