erf() - The Gauss error function

[bplus]

https://en.wikipedia.org/wiki/Error_function

... only a function, but a nice function!
Isn't it?

Looks like a great way to make the letter S continuous over infiniy in both directions.
erf# ? A: Is the sound the S makes being stretched like that ;-))

Haven't I seen something like this function for Neural Net setup and training?