auto-surprise 0.1.9

A python package that automates algorithm selection and hyperparameter tuning for the recommender system library Surprise

Auto-Surprise

Auto-Surprise is built as a wrapper around the Python Surprise recommender-system library. It automates algorithm selection and hyper parameter optimization in a highly parallelized manner.

• Documentation is available at Auto-Surprise ReadTheDocs
• AutoSurprise is currently in development.

Setup

Auto-Surprise is easy to install with Pip, and required Python>=3.6 installed on a linux system. Currently not supported in windows, but can be used using WSL.

$ pip install auto-surprise

Usage

Basic usage of AutoSurprise is given below.

from surprise import Dataset
from auto_surprise.engine import Engine

# Load the dataset
data = Dataset.load_builtin('ml-100k')

# Intitialize auto surprise engine
engine = Engine(verbose=True)

# Start the trainer
best_algo, best_params, best_score, tasks = engine.train(
    data=data, 
    target_metric='test_rmse', 
    cpu_time_limit=60 * 60, 
    max_evals=100
)

In the above example, we first initialize the Engine. We then run engine.train() to begin training our model. To train the model we need to pass the following

• data : The data as an instance of surprise.dataset.DatasetAutoFolds. Please read Surprise Dataset docs
• target_metric : The metric we seek to minimize. Available options are test_rmse and test_mae.
• cpu_time_limit : The time limit we want to train. This is in seconds. For datasets like Movielens 100k, 1 hour is sufficient. But you may want to increase this based on the size of your dataset
• max_evals: The maximum number of evaluations each algorithm gets for hyper parameter optimization.
• hpo_algo: Auto-Surprise uses Hyperopt for hyperparameter tuning. By default, it's set to use TPE, but you can change this to any algorithm supported by hyperopt, such as Adaptive TPE or Random search.

Setting the Hyperparameter Optimization Algorithm

Auto-Surprise uses Hyperopt. You can change the HPO algo as shown below.

# Example for setting the HPO algorithm to adaptive TPE
import hyperopt

...

engine = Engine(verbose=True)
engine.train(
    data=data,
    target_metric='test_rmse',
    cpu_time_limit=60 * 60,
    max_evals=100,
    hpo_algo=hyperopt.atpe.suggest
)

Building back the best model

You can build a pickelable model as shown.

model = engine.build_model(best_algo, best_params)

Benchmarks

In my testing, Auto-Surprise performed anywhere from 0.8 to 4% improvement in RMSE compared to the best performing default algorithm configuration. In the table below are the results for the Jester 2 dataset. Benchmark results for Movielens and Book-Crossing dataset are also available here

Algorithm	RMSE	MAE	Time
Normal Predictor	7.277	5.886	00:00:01
SVD	4.905	3.97	00:00:13
SVD++	5.102	4.055	00:00:29
NMF	--	--	--
Slope One	5.189	3.945	00:00:02
KNN Basic	5.078	4.034	00:02:14
KNN with Means	5.124	3.955	00:02:16
KNN with Z-score	5.219	3.955	00:02:20
KNN Baseline	4.898	3.896	00:02:14
Co-clustering	5.153	3.917	00:00:12
Baseline Only	4.849	3.934	00:00:01
GridSearch	4.7409	3.8147	80:52:35
Auto-Surprise (TPE)	4.6489	3.6837	02:00:10
Auto-Surprise (ATPE)	4.6555	3.6906	02:00:01

Papers

Auto-Surprise: An Automated Recommender-System (AutoRecSys) Library with Tree of Parzens Estimator (TPE) Optimization