Point Graph and Derivative

[Ming Chen]

Hi, Gurus.
I'm using Excel for one of my classes and having this problem. Let's say,
I have a number of sample {x, y} pairs. I have produced a correlation graph
y = f(x) with XY (Scatted), and have the line smoothed.
But what I really care about is not f(x), but f'(x) = dy/dx, the
derivative of f(x). So, my question is, with only the graph I have got, is
there a way to produce a derivative graph of f(x) in excel?

Thanks
Ming Chen

 

[Tushar Mehta]

Use David Braden's cubic splines algorithm
(http://groups.google.com/groups?selm=3A11AD33.B1438202%
40rochester.rr.com) or the bezier curve solution at
http://xlrotor.com/Excel_Stuff.htm

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

 

[Ming Chen]

That's great.
Thanks.

Use David Braden's cubic splines algorithm
(http://groups.google.com/groups?selm=3A11AD33.B1438202%
40rochester.rr.com) or the bezier curve solution at
http://xlrotor.com/Excel_Stuff.htm

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

 

[Bernard Liengme]

Play with adding trendlines until you get a good fit (2nd, 3rd, 4th order
Use LINEST to get the fit parameters in cells (see my website)
Differential the equation of best fit