Fig. 3.

Relationship between prediction accuracy and its predicted amplitude for ratio TimeMachine and $Z$-score TimeMachine. The amplitude here is defined as the magnitude of the predictor $\widehat{Y}$. Predicted amplitudes $\le$0.5 yield a significantly less accurate time prediction than higher amplitudes for both variants of TimeMachine ($P<0.001$; Wilcoxon rank-sum test).