Excel - S curve Calculation in Excel.

Asked By nate.bloc on 28-Feb-09 02:10 AM
Hello all.  I'd like to find a basic formula for an S curve calc in
excel.  Variables would be equal to Y = moeny vs. X time (or period).
Ymax would be the budgeted cost of the project, and Xmax would be the
budgeted time for the project.

current calculation I'm using is:

Y = Ymax ((2(X/Xmax)^2) - (X/Xmax)^4)

While this does give me a curve, I need a curvier curve.  :-)  Any
help would be appreciated.


Mike Middleton replied on 25-Feb-09 01:37 PM
nate.block  -

Consider a logistic function. For details, search Google for "excel logistic
curve" (without the quote marks).

For "curvier curve," consider more XY pairs, perhaps using an XY (Scatter)
chart type instead of a Line chart type, and choose "Smoothed line."

For more assistance, specify your version of Excel.

-  Mike