Re: [R] abline in log-log power law plot

From: Peter Dalgaard <p.dalgaard_at_biostat.ku.dk>
Date: Fri, 22 Feb 2008 23:32:37 +0100

hadley wickham wrote:
> On Fri, Feb 22, 2008 at 2:38 PM, martin klein <mklein@cs.odu.edu> wrote:
>
>> I have a power law plot in log-log scale using plot(x,y,log="xy") but I
>> can't get the regression line to plot correctly.
>> abline(lm(log(y)~log(x))) plots a straight line that looks promising but
>> the intercept with the y-axis seems to be way off.
>> summary(lm(log(y)~log(x))) gives the values but i cant really make any
>> sense out of it.
>> fitted(..) just confirms the values that seem to be incorrect.
>> any help is appreciated.
>> thanks!
>>
>
> You might try using ggplot2 instead:
>
> install.packages("ggplot2")
> library(ggplot2)
>
> qplot(x, y, log="xy") + geom_smooth(method = lm)
>
> Hadley
>
>
Or just switch to base-10 logarithms:

abline(lm(log10(y)~log10(x)))

-- 
   O__  ---- Peter Dalgaard             ุster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard_at_biostat.ku.dk)                  FAX: (+45) 35327907

______________________________________________
R-help_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Received on Fri 22 Feb 2008 - 22:36:41 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Fri 22 Feb 2008 - 23:30:16 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive