How generate trendline equations for Power, Exp and Log trendlines
 

I am able to generate polynomial coefficients that match using LINEST but I
wonder if anyone knows how to get the coefficients and exponents for the
other type of trendlines.

Thanks

have you tried graphing the data and adding the different trendlines with
option for equation to be shown? Note you will normally need to increase the
number of decimal places shown.

"Incoherent" wrote:

I am able to generate polynomial coefficients that match using LINEST but I
wonder if anyone knows how to get the coefficients and exponents for the
other type of trendlines.

Thanks

The archives of these newsgroups are generally a good place to start

http://groups.google.com/group/micro...687207210e1cde

Jerry

Incoherent wrote:

I am able to generate polynomial coefficients that match using LINEST but I
wonder if anyone knows how to get the coefficients and exponents for the
other type of trendlines.

Thanks

Thanks for the reply.
I would typically be using this in a template where the raw data changes. I
want a formula to do this rather than copy/paste from a chart.



"bj" wrote:

have you tried graphing the data and adding the different trendlines with
option for equation to be shown? Note you will normally need to increase the
number of decimal places shown.

"Incoherent" wrote:

I am able to generate polynomial coefficients that match using LINEST but I
wonder if anyone knows how to get the coefficients and exponents for the
other type of trendlines.

Thanks

Thanks again Jerry. That linked post gets me half way, I see one of the
coefficients in each case but the intercept is eluding me. I'll play around a
bit.
Interesting that the trendline numbers differ after about 10 decimal places...

"Jerry W. Lewis" wrote:

The archives of these newsgroups are generally a good place to start

http://groups.google.com/group/micro...687207210e1cde

Jerry

Incoherent wrote:

I am able to generate polynomial coefficients that match using LINEST but I
wonder if anyone knows how to get the coefficients and exponents for the
other type of trendlines.

Thanks

I just found this site

http://j-walk.com/ss/excel/tips/tip101.htm

It should do what you want

"Incoherent" wrote:

Thanks for the reply.
I would typically be using this in a template where the raw data changes. I
want a formula to do this rather than copy/paste from a chart.



"bj" wrote:

have you tried graphing the data and adding the different trendlines with
option for equation to be shown? Note you will normally need to increase the
number of decimal places shown.

"Incoherent" wrote:

I am able to generate polynomial coefficients that match using LINEST but I
wonder if anyone knows how to get the coefficients and exponents for the
other type of trendlines.

Thanks

Cool, thanks for that. I had figured out some of it, this completes the rest.



"bj" wrote:

I just found this site

http://j-walk.com/ss/excel/tips/tip101.htm

It should do what you want

"Incoherent" wrote:

Thanks for the reply.
I would typically be using this in a template where the raw data changes. I
want a formula to do this rather than copy/paste from a chart.



"bj" wrote:

have you tried graphing the data and adding the different trendlines with
option for equation to be shown? Note you will normally need to increase the
number of decimal places shown.

"Incoherent" wrote:

I am able to generate polynomial coefficients that match using LINEST but I
wonder if anyone knows how to get the coefficients and exponents for the
other type of trendlines.

Thanks

If you do a Google search among the Groups, you will find "Code Post:
Extract Trendline coefficients" by David J. Braden, dated Mar 5 2003.
Related code is at "Code Post: Trendline/Regression Routines", Jul 23 1999,
David J. Braden

"Incoherent" wrote in message
...
I am able to generate polynomial coefficients that match using LINEST but I
wonder if anyone knows how to get the coefficients and exponents for the
other type of trendlines.

Thanks