Add Length of Stay Dataset and Prediction Task

[tanub22]

Author: Muni T. Bondu

Type of contribution: Dataset and Task

High level description:
I've implemented a Length of Stay (LOS) prediction dataset and task for PyHealth. This contribution includes:

• LOSDataset: A BaseDataset implementation for hospital admission/discharge data
• LOSTask: A BaseTask implementation for predicting length of stay based on temporal admission features
• Synthetic sample data generator for testing
• YAML configuration following PyHealth standards
• Example usage with scikit-learn for demonstration

Files to review for testing:

• pyhealth/contrib/tasks/length_of_stay/task.py - Main implementation
• pyhealth/contrib/tasks/length_of_stay/lengthofstay.yaml - Configuration file
• pyhealth/contrib/tasks/length_of_stay/fake_los_data.csv - Sample data

Test case: Run python task.py in the length_of_stay directory to see the full demo including:

• Dataset loading and processing
• Task creation and feature extraction
• call method testing
• Simple prediction model example