`scale_protti`

is used to scale a numeric vector either between 0 and 1 or around a
centered value using the standard deviation. If a vector containing only one value or
repeatedly the same value is provided, 1 is returned as the scaled value for `method = "01"`

and 0 is returned for `metod = "center"`

.

`scale_protti(x, method)`

- x
a numeric vector

- method
a character value that specifies the method to be used for scaling. "01" scales the vector between 0 and 1. "center" scales the vector equal to

`base::scale`

around a center. This is done by subtracting the mean from every value and then deviding them by the standard deviation.

A scaled numeric vector.

```
scale_protti(c(1, 2, 1, 4, 6, 8), method = "01")
#> [1] 0.0000000 0.1428571 0.0000000 0.4285714 0.7142857 1.0000000
```