Figure 4.

The $\overline{\text{RMSE}}$ (averaged across simulations and modalities) versus the number of modalities used in a RWT experiment. A sharp decline in $\overline{\text{RMSE}}$ is seen from one to two modalities, followed by a slow decline. One might expect this, especially because RWT cannot work properly with only one modality. The performance of conventional regression analysis is independent of the number of modalities. The same model parameters were used for all modalities in all experiments (a_m = 1, b_m = 0.1, σ_m = 0.05, P = 100).