How can I plot my R Squared value on my scatterplot using R?

Question

This seems a simple question, so I hope its a simple answer. I am plotting my points and fitting a linear model, which I can do OK. I then want to plot some summary statistics, for example the R Squared value, on the plot also. I can only seem to get the R Squared value at the command line. Any advice; do I need to be looking at ggplot or anything else? Thanks in advance.

#Does the plot
plot(df$VAR1, df$VAR2)
#Adds the line
abline(lm(df$VAR2~df$VAR1), col="red")
#Shows stats on command line
summary(lm(df$VAR2~df$VAR1))

Dirk Eddelbuettel · Accepted Answer · 2016-11-12T23:15:28.853

34

You can abuse legend() because it has the handy logical placement:

R> DF <- data.frame(VAR1=rnorm(100), VAR2=rnorm(100))
R> with(DF, plot(VAR1, VAR2))
R> abline(fit <- lm(VAR2 ~ VAR1, data=DF), col='red')
R> legend("topright", bty="n", legend=paste("R2 is", 
+         format(summary(fit)$adj.r.squared, digits=4)))

Here bty="n" suppresses the box, and you need format() to shorten the display. Other text() is good, as are arguments main= and sub= to plot().

edited Nov 12 '16 at 23:15

answered Sep 21 '10 at 14:48

Dirk Eddelbuettel

360,940
56
644
725

Thanks for the quick response. Seems to work, don't think I would have thought of that in a hurry! – phrozenpenguin Sep 21 '10 at 15:04
Apologies - still getting used to how this all works. I think thats accepted now.. – phrozenpenguin Sep 23 '10 at 13:13
2

No apology needed. At some point each one of us was new here, and we're all learning together. – Dirk Eddelbuettel Sep 23 '10 at 14:07

score 7 · Answer 2 · edited Sep 21 '10 at 15:58

7

The text function places text into the current plot, it is one option for adding the r-squared value to a plot. Also look at the grconvertX and grconvertY functions for ways to find the location to place the text.

The corner.label and emptyspace functions in the plotrix package may also help.

edited Sep 21 '10 at 15:58

nico

50,859
17
87
112

answered Sep 21 '10 at 15:13

Greg Snow

48,497
6
83
110

Thanks for the alternative option. I'm already used to using legend so will stick with that for now. – phrozenpenguin Sep 23 '10 at 13:13

How can I plot my R Squared value on my scatterplot using R?

2 Answers2

Linked