Adding a logistic function into the wrapper?

[zceydas]

Thanks for developing this function! I'm very new to JS and need to fit a logistic function to my dataset. I was wondering how I could implement the curve '1 / (1 + (exp(x)*c))' in your curve fitting wrapper. Any recommendations? Or are there any useful links you can share? Thanks in advance!

[bvandenbon]

I have similar questions, either looking for a "sigmoid" or a "tanh"

(e.g. see tanh below)