Re: [R] Question about 'text' (add lm summary to a plot)

From: Christoph Buser <buser_at_stat.math.ethz.ch>
Date: Thu 21 Jul 2005 - 23:18:11 EST

Dear Dan

I can only help you with your third problem, expression and paste. You can use:

plot(1:5,1:5, type = "n")
text(2,4,expression(paste("Slope : ", 3.45%+-%0.34, sep = "")), pos = 4)
text(2,3.8,expression(paste("Intercept : ", -10.43%+-%1.42)), pos = 4)
text(2,3.6,expression(paste(R^2,": ", "0.78", sep = "")), pos = 4)

I do not have an elegant solution for the alignment.

Regards,

Christoph Buser



Christoph Buser <buser@stat.math.ethz.ch> Seminar fuer Statistik, LEO C13
ETH (Federal Inst. Technology)	8092 Zurich	 SWITZERLAND
phone: x-41-44-632-4673		fax: 632-1228

http://stat.ethz.ch/~buser/

Dan Bolser writes:
>
> I would like to annotate my plot with a little box containing the slope,
> intercept and R^2 of a lm on the data.
>
> I would like it to look like...
>
> +----------------------------+
> | Slope : 3.45 +- 0.34 |
> | Intercept : -10.43 +- 1.42 |
> | R^2 : 0.78 |
> +----------------------------+
>
> However I can't make anything this neat, and I can't find out how to
> combine this with symbols for R^2 / +- (plus minus).
>
> Below is my best attempt (which is franky quite pour). Can anyone
> improve on the below?
>
> Specifically,
>
> aligned text and numbers,
> aligned decimal places,
> symbol for R^2 in the text (expression(R^2) seems to fail with
> 'paste') and +-
>
>
>
> Cheers,
> Dan.
>
>
> dat.lm <- lm(dat$AVG_CH_PAIRS ~ dat$CHAINS)
>
> abline(coef(dat.lm),lty=2,lwd=1.5)
>
>
> dat.lm.sum <- summary(dat.lm)
> dat.lm.sum
>
> attributes(dat.lm.sum)
>
> my.text.1 <-
> paste("Slope : ", round(dat.lm.sum$coefficients[2],2),
> "+/-", round(dat.lm.sum$coefficients[4],2))
>
> my.text.2 <-
> paste("Intercept : ", round(dat.lm.sum$coefficients[1],2),
> "+/-", round(dat.lm.sum$coefficients[3],2))
>
> my.text.3 <-
> paste("R^2 : ", round(dat.lm.sum$r.squared,2))
>
> my.text.1
> my.text.2
> my.text.3
>
>
> ## Add legend
> text(x=3,
> y=300,
> paste(my.text.1,
> my.text.2,
> my.text.3,
> sep="\n"),
> adj=c(0,0),
> cex=1)
>
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R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Jul 21 23:37:31 2005

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