ForecastGrapher: Redefining Multivariate Time Series Forecasting with Graph Neural Networks
Wanlin Cai, Kun Wang, Hao Wu, Xiaoxu Chen, Yuankai Wu
TL;DR
ForecastGrapher reframes multivariate time series forecasting as node regression on a graph, treating each variate as a node with temporal embeddings and a layer-wise self-learnable adjacency A^l to capture inter-series correlations. Its core novelty, the Group Feature Convolution GNN (GFC-GNN), diversifies node feature distributions by partitioning embeddings into G groups and applying kernel-length varied 1D convolutions, followed by a residual fusion to produce forecasts. Across twelve benchmarks, ForecastGrapher achieves state-of-the-art results, notably on high-dimensional datasets like Electricity and PEMS, and ablation studies validate the importance of variate embeddings, adaptive graphs, and the GFC mechanism. The work offers a flexible, end-to-end framework that extends GNNs’ expressive power for long-horizon MVTS forecasting and provides a foundation for broader time-series analysis tasks with interpretable inter-series relationships.
Abstract
The challenge of effectively learning inter-series correlations for multivariate time series forecasting remains a substantial and unresolved problem. Traditional deep learning models, which are largely dependent on the Transformer paradigm for modeling long sequences, often fail to integrate information from multiple time series into a coherent and universally applicable model. To bridge this gap, our paper presents ForecastGrapher, a framework reconceptualizes multivariate time series forecasting as a node regression task, providing a unique avenue for capturing the intricate temporal dynamics and inter-series correlations. Our approach is underpinned by three pivotal steps: firstly, generating custom node embeddings to reflect the temporal variations within each series; secondly, constructing an adaptive adjacency matrix to encode the inter-series correlations; and thirdly, augmenting the GNNs' expressive power by diversifying the node feature distribution. To enhance this expressive power, we introduce the Group Feature Convolution GNN (GFC-GNN). This model employs a learnable scaler to segment node features into multiple groups and applies one-dimensional convolutions with different kernel lengths to each group prior to the aggregation phase. Consequently, the GFC-GNN method enriches the diversity of node feature distribution in a fully end-to-end fashion. Through extensive experiments and ablation studies, we show that ForecastGrapher surpasses strong baselines and leading published techniques in the domain of multivariate time series forecasting.
