userdefined trendline

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

I need constract trendline with equation y=a1*EXP(a2/(x-a3))+a4 using Excel.
(a1..a4 are to define)
Could you please advise me how one can do it?
Thanks a lot.
 
Andy Pope has covered the plotting of the function. By "(a1..a4 are to
define)" you mean that you also want to know how to fit the coefficients?

If so, suppose that cells A1:A4 are used to hold trial values for
a1..a4. Array enter (Ctrl-Shift-Enter) the following formula
=SUM((yData-(A1*EXP(A2/(x-A3))+A4))^2)
and use Solver to minimize that formula by changing cells A1:A4.

Jerry
 
Back
Top