This function computes the root mean square error (RMSE) between a vector of
observed values `x`

and simulated values `y`

. `rel = FALSE`

returns the absolute RMSE, `rel = TRUE`

the relative one. If
`na.rm`

is `TRUE`

, missing values are omitted before the
computation proceeds.

## Usage

`rmse(x, y, rel = F, na.rm = T)`

## Arguments

- x
a numeric vector containing observed values.

- y
a numeric vector containing simulated values.

- rel
logical. If `TRUE`

, the relative RMSE is calculated, if
`FALSE`

the absolute RMSE is returned.

- na.rm
logical. Should missing values be removed?

## Author

Zacharias Steinmetz

## Examples

```
rmse(c(0.12,0.59,NA), c(0.15,0.63,1.2))
#> [1] 0.03535534
```