# e

##### e

Calculates the Nash-Sutcliffe modelling efficiency (E) from observed and predicted values.

##### Usage

`e(o, p)`

##### Arguments

- o
A numeric vector. Observed values.

- p
A numeric vector. Predicted values.

##### Details

Interpretation: a value of 1 means that all predicted values are equal to the observed values. A value of 0 means that the predictions explain as much of the variation in the observed values as the mean of the observed values does. A negative value means that the predictions are less accurate the mean of the observed values.

##### Value

Nash-Sutcliffe modelling efficiency (E).

##### References

Nash, J. E., & Sutcliffe, J. V. (1970). River flow forecasting through conceptual models part I. A discussion of principles. Journal of hydrology, 10(3), 282-290.

Piikki K., Wetterlind J., Soderstrom M., Stenberg B. (2021). Perspectives on validation in digital soil mapping of continuous attributes. A review. Soil Use and Management. 10.1111/sum.12694

Wilks D. S. (2011) Statistical Methods in the Atmospheric Sciences, Academic Press, Oxford, UK.

##### Examples

```
# NOT RUN {
obs<-c(1:10)
pred<-c(1, 1 ,3, 2, 4, 5, 6, 8, 7, 10)
e(o=obs, p=pred)
# }
```

*Documentation reproduced from package valmetrics, version 1.0.0, License: MIT + file LICENSE*