2.6.2. Relative RMSE (rRMSE)

The relative RMSE is the ratio of the RMSE to the mean values of field measurements (yield (t ha<sup>−</sup>1)):

$$\text{rRMSE} = \frac{\text{RMSE}}{\frac{\sum\_{i=1}^{N} O i}{N}} \tag{2}$$

where *O* represents the observed value and *N* represents the number of samples.
