icomb - Forecasting Hierarchical Time Series Using Information Combination

Implements the Information Combination (IComb) approach proposed by Nguyen, Vahid and Wickramasuriya (2025)<https://www.monash.edu/business/ebs/research/publications/ebs/2025/wp11-2025.pdf> for hierarchical forecast reconciliation. The method combines information from base forecasts constructed using different information sets while ensuring coherence. It is implemented using a penalized regression-based framework.