# Series expansion of a sigmoid

1. Nov 22, 2011

### hak185

I am just curious to know if it is possible to derive a series expansion for the following sigmoid equation:

base + max/(1+exp(H-x/rate))

where the coefficients are base, max, H, and rate.

Would appreciate any insight.

2. Nov 22, 2011

### hak185

Seem like I can infer from the ratio of responses to views that this is not a very feasible concept...? In any case, I would appreciate any type of feedback. I would just like to get an idea of how attainable the derivation is, especially from someone who is knowledgable on applying taylor series expansion to functions.

3. Nov 23, 2011

What type of series are you interested in? Taylor?
You can use wolframalpha's symbolic calculator: http://www.wolframalpha.com/input/?i=series+b+++m/(1+exp(H-x/r))