Chris,
I haven't seen anyone post a reply yet so thought I'd
throw in my thoughts. I'm no R expert!
When you talk about an exponential trend line are you
refering to:
1) y=ax^b
or
2) y=ae^(bx)
If 1) then take base10 logs of y and x and then fit them
with simple linear regression. Then calculate the antilog
of the residulas and plot these as your trendline.
If 2) then take natural logs of y and x and follow the rest
of the procedure described in 1).
Hope this helps.
Murray M Cooper, Ph.D.
Richland Statistics
9800 N 24th St
Richland, MI, USA 49083
Mail: richs...@earthlink.net
----- Original Message -----
From: "chrisli1223" <chri...@austwaterenv.com.au>
To: <r-help@r-project.org>
Sent: Thursday, January 07, 2010 10:33 PM
Subject: [R] R exponential regression
Hi all,
I have a dataset which consists of 2 columns. I'd like to plot them on a
x-y
scatter plot and fit an exponential trendline. I'd like R to determine the
equation for the trendline and display it on the graph.
Since I am new to R (and statistics), any advice on how to achieve this
will
be greatly appreciated.
Many thanks,
Chris
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