How can I combine text and math expressions in a plot's title. If I use paste the expression is converted to character. For example I want something like this as a title
$ARL_1$ curve for $S^2$
Thank you
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3 Answers
You want to read ?plotmath to see how to do this sort of thing. Here is an example:
plot(1:10, main = expression(ARL[1] ~ "curve for" ~ S^2))
The [.] is subscript, whilst ^ gives superscript. The ~ spaces out the parts of the expression as if there were literal spaces.
Edit: normally I would have done:
plot(1:10, main = expression(ARL[1] ~ curve ~ for ~ S^2))
but that throws an error because for is being interpreted as the start of a for() loop call.
3 Comments
Marek
Second will work if you use
expression(ARL[1] ~ curve ~ "for" ~ S^2).
Gavin Simpson
@Marek: Oh, yes, agreed. But if you are going to do
"for" you might as well do "curve for", unless ~ and " " are different amounts of space...?Marek
Of course. It matters in more complicated cases when one needs to mixed more strings. I add it as completeness ;) On other hand you could also use back-ticks
`.You can also use bquote(paste(...)), which is a little more flexible than expression: you can include variable values (say, the value of x) in the labels with .(x). For example:
x<- 232323
plot(1:10, main = bquote(paste(ARL[1], " curve for ", S^2, "; x=",.(x))))
5 Comments
IRTFM
Yes although I generally find that using the plotmath paste function confuses more than it helps. Try > x<- 232323 > plot(1:10, main = bquote(ARL[1]~"curve for"~S^2~";"~x==.(x)))
Gavin Simpson
+1 Dwin - introducing
paste is a pain in the but if you get your , or "" in the wrong places...
fabians
@GavinSimpson Yeah, your answer is nicer. But I thought it would be good to point out a more flexible solution in case somebody comes here looking for a more general solution.
Gavin Simpson
+1 from me. That comment wasn't a criticism of the substantive point of your answer (
bquote()), just a point about introducing paste in there if you can avoid it. bquote() is underused and very powerful!IRTFM
.. another 1+ from me. I thought bquote was an excellent suggestion and only added a very minor demurral to avoid paste when possible, because it often gets confused with that "other paste". People don't realize it's a different function with different sematics and with no sep argument.
You can also use latex2exp::TeX to convert TeX to expressions on the fly:
plot(cars, main = TeX("$ARL_1$ curve for $S^2$"))
