GARDiff: Graph-Aligned Residual Diffusion for Probabilistic Multivariate Time-Series Forecasting
Authors: Rui Han, Min Yang, Xu Zhang, Xinghao Yang, Wei Liu, Yongshun Gong
Organizations: Shandong University, Jinan, China · Macquarie University, Sydney, Australia · China University of Petroleum (East China), Qingdao, China · University of Technology Sydney, Sydney, Australia
Diffusion models have recently shown strong potential for probabilistic multivariate time-series forecasting by modeling complex conditional distributions. Recent decoupled diffusion frameworks further separate forecasting into deterministic prediction and stochastic residual generation, making it natural to derive dependency graphs from deterministic representations and use them to guide residual diffusion. However, we show that this direct structural transfer is unreliable. Although deterministic-derived graphs encode useful global dependency priors, they exhibit substantial edge-level misalignment with residual dependency structures, introducing inaccurate or redundant conditions during residual generation. This reveals a previously overlooked deterministic-to-residual structural alignment problem in decoupled diffusion forecasting. To address this problem, we propose GARDiff, a Graph-Aligned Residual Diffusion framework for probabilistic multivariate time-series forecasting. Instead of treating deterministic-derived graphs as fixed diffusion conditions, GARDiff progressively adapts them to residual generation. Specifically, GARDiff estimates residual uncertainty to distinguish high- and low-uncertainty regions, enabling uncertainty-aware structural refinement, and further performs timestep-aware edge sparsification during reverse diffusion to evolve graph conditions from broad dependency aggregation to localized residual refinement. Extensive experiments on six real-world benchmarks demonstrate that GARDiff consistently improves probabilistic forecasting performance and uncertainty calibration over strong baselines.
Figures & tables
Figure 1: (a) Comparison between existing diffusion forecasting and the decoupled forecasting paradigm. Decoupling deterministic and uncertainty modeling enables the deterministic stage to provide structural priors for uncertainty-aware residual diffusion. (b) Quantitative evidence of structural mismatch between deterministic-derived and residual-derived graphs.
Figure 2: Overview of GARDiff. The deterministic forecasting module extracts representations and constructs a structural prior graph. The graph alignment module refines the prior using residual uncertainty and diffusion timestep. The graph-conditioned diffusion module then performs residual generation with dynamic structural guidance.
Model
ETTm1
ETTm2
Weather
Solar
ECL
Traffic
CRPS
CRPSsum
CRPS
CRPSsum
CRPS
CRPSsum
CRPS
CRPSsum
CRPS
CRPSsum
CRPS
CRPSsum
TimeDiff
0.490
2.195
0.320
1.597
0.302
2.625
0.700
2.408
0.735
1.966
0.766
1.885
TMDM
0.380
1.665
0.298
1.412
0.244
1.915
0.355
1.534
0.438
1.573
0.453
1.587
NsDiff
0.394
1.878
0.315
1.564
0.230
1.971
0.273
0.951
0.285
0.874
0.319
0.864
D3U
0.283
0.801
0.247
0.114
0.208
0.248
0.174
0.604
0.202
0.665
0.224
0.786
Ours
0.273
0.744
0.234
0.093
0.199
0.220
0.166
0.463
0.191
0.459
0.212
0.459
Table 1: Probabilistic forecasting performance. All results are reported with input length H=96 and averaged over three forecasting horizons ( L∈{96,192,336} ). Best results are highlighted in bold . See Table 6 for full results.
Model
ETTm1
ETTm2
Weather
Solar
ECL
Traffic
MSE
MAE
MSE
MAE
MSE
MAE
MSE
MAE
MSE
MAE
MSE
MAE
Point Forecasting Models
PatchTST
0.359
0.381
0.247
0.304
0.227
0.258
0.242
0.275
0.177
0.263
0.455
0.287
TimesNet
0.386
0.404
0.254
0.307
0.225
0.263
0.251
0.272
0.186
0.288
0.613
0.325
iTransformer
0.381
0.397
0.252
0.312
0.227
0.257
0.231
0.257
0.164
0.256
0.411
0.276
TimeBridge
0.360
0.375
0.244
0.307
0.221
0.248
0.220
0.230
0.155
0.256
0.411
0.273
Table 2: Deterministic forecasting performance. All results are reported with input length H=96 and averaged over three forecasting horizons ( L∈{96,192,336} ). Best results are highlighted in bold . See Table 7 for full results.
Dataset
Setting
MSE
MAE
CRPS
CRPSsum
ETTm1
Pred. Unc.
0.345
0.375
0.273
0.744
Oracle Res.
0.346
0.375
0.272
0.751
Weather
Pred. Unc.
0.222
0.268
0.202
0.220
Oracle Res.
0.222
0.268
0.202
0.220
Table 3: Performance comparison between predicted uncertainty and oracle residuals. Results are reported with input length H=96 and averaged over three forecasting horizons ( L∈{96,192,336} ). See Table 9 for full results.
School of Information and Electronic Engineering (Sussex Artificial Intelligence Institute), Zhejiang Gongshang University, Hangzhou, Zhejiang, China · School of Computer Science, University of Auckland, Auckland, New Zealand
Department of Industrial and Systems Engineering, University of Miami, United States of America · Department of Computer Science, University of Miami, United States of America
University of New South Wales Sydney, Australia · University of Maryland College Park, United States · The Hong Kong University of Science and Technology (Guangzhou) Guangzhou, China