I would like to have the title for the plot in two lines, but this does not work, why? and how can I make it work?
CVal<-1
SumEpsVal<-2
plot(1:10, main=bquote(paste("C=", .(CVal), " \n ", sum(xi), "=", .(SumEpsVal) )))
This here works:
plot(1:10, main=paste("C=1", "\n", "SumXi=2"))
I guess bquote makes something wrong... (look up ?bquote)
I tried to change environment in bqoute (the where-argument) but I don't know which environment to take.
BTW:
plot(1:10, main=bquote(paste("C=", .(CVal), "bla \n ", sum(xi), "=", .(SumEpsVal) )))
makes something crazy with the "bla".
Personally I would use mtext as already suggested. But if you really want it to be a one-liner, you can "cheat" bquote by using atop:
plot(1:10, main=
bquote(atop(paste("C=",.(CVal)), paste(sum(xi),"=",.(SumEpsVal)))))
It even aligns both lines neatly to the center.
The root issue is that plotmath does not support newlines within the
expressions to be output.
Control characters (e.g. \n) are not interpreted in character strings in plotmath,
unlike normal plotting.
You really need to create and output each line separately.
For example :
Lines <- list(bquote(paste("C=", .(CVal))),
bquote(paste(sum(xi), "=", .(SumEpsVal))))
Now output each line The text in the list is converted to expressions do.call
mtext(do.call(expression, Lines),side=3,line=0:1)
One way to achieve this is to use mtext to add an additional line under the main title as follows:
plot(1:10, main=bquote(paste("C=", .(CVal))))
mtext(bquote(paste(sum(xi), "=", .(SumEpsVal) )),side=3,line=0)
There may be a prettier solution, but perhaps this is enough for your needs.
Related
Specifying text in a base R plot() with formatting such as italics / bold font / newline usually involves one or more of the following functions:
paste()
expression()
atop()
substitute()
italic()
Is there an intuitive explanation for the differences between these functions and when best to apply them?
What you're referring to is the plotmath syntax.
To start off, let's make it clear that for a plotmath expression to be interpreted as such, you tell R it's an "expression" and that is why you need expression().
So any time you want to use special symbols or formatting, like italic() and atop(), it's actually a part of plotmath and so you need to wrap it in an expression. eg:
plot(0, main = expression(atop(over,italic(under))))
If you've tried out ?italic or ?atop, you've probably noticed it takes you straight to the plotmath manual page, where a bunch of other functions are listed.
What about substitute() ? Well in my previous example, you'll notice I used strings directly to write 'over' and 'under', without putting them within quotes. This is because of the special expression() environment.
So if you need to put whatever is inside a variable in your text (rather than the variable name) then you put your expression inside a substitute() and give it the arguments. eg:
plot(0, main = substitute(atop(oo,italic(under))), list(oo='over2')))
Note that we don't put substitute around the expression block but replace it entirely.
Finally, where does paste() come in all this ? Well, paste is the glue (pun intended) with any text not dealt with by plotmath.
So if you need text before or after math symbols (or formatted text), you paste() things together within the expression (or substitute) environment. eg :
plot(0, main = substitute(paste("b4", atop(oo,italic(under)), aft),
list(oo='over', aft = 'after3')))
As before, if you want to paste the content of a variable, you need substitute.
And Voilà that's most of the plotmath you'll ever need!
For any other symbols, or functions, have look at ?plotmath
I've learned to apply bold to a portion of the text used in a plot title using mtext() expression() and paste(). This works great if you specify the strings outright. However, in the project I'm working on now, the portion of text to be bolded needs to be obtained through a call to an element of a vector. However, the characters needed in the call syntax are interpreted by expression() and the call fails.
junk <- c("I'm Special", "You're Special")
plot(0, type="n")
mtext(expression(paste("Do you think ", bold(junk[1]),"today?")),3,2)
mtext(expression(paste("I think ", bold(junk[2]), "today.")),3,1)
Any thoughts on how to approach this? I am trying to avoid specifying the bold text directly.
bquote has a decent interface for this. You just surround the variable you want to substitute with .(). You could also use substitute with expression.
junk <- c("I'm Special", "You're Special")
plot(0, type="n")
mtext(bquote(paste("Do you think ", bold(.(junk[1])),"today?")),3,2)
mtext(bquote(paste("I think ", bold(.(junk[2])), "today.")),3,1)
I make some plots with R and use bquote because I need variables for the main of the plot. However, the main is no longer bold but I want it to be bold. I defined the main as follows:
title = bquote(atop("Empirical Pricing Kernel at Date",~.(EndDate)~"with Index Price"~.(ST)~"€"))
plot(temp, EPK, type="l", main = title)
Enddate contains "2014-08-01" as date and ST is just numeric with 9210.08.
Is there any way to make it bold with or without bquote? I'd like to find a solution with bquote because it's very convenient when using subscripts.
My problem is that I am using it in a par-plot with two plots and the other plot needs no special things in it's main. So, the main is bold. I even tried to just put bquote around it in order to get the same font size but it stayed bold.
I prefer to use what I think of as "pure plotmath" so I use tilde's instead of spaces and use no quotes. I suspect it was the leading tilde in the second argument to bquote that was throwing the error. In plotmath the tildes need something on either side: If you really need a none-displayed something you can always use phantom(0) but why bother in this case?
bquote(atop(Empirical~Pricing~Kernel~at~Date,
bold(.(EndDate))~with~Index~Price~.(ST)~"€"
) )
Test:
EndDate="2014-08-01";ST=9210.08
title = bquote(atop(Empirical~Pricing~Kernel~at~Date, bold(.(EndDate))~with~Index~Price~.(ST)~"€"))
plot(1,1, type="l", main = title)
How would you add a subscript to one particular word of a title in R? For example, suppose the title is "A_2 and B_2." How would you add these two subscripts? I know that expression("A"[2]) and expression("B"[2]) individually add subscripts to these letters.
You do not need paste (or quotes for that matter) at all:
expression( A[2]~and~B[2] )
Test:
plot(1,1, main=expression( A[2]~and~B[2] ) )
The syntactic principle is that tildes (which creates a space) and asterisks (non-space plotmath separator) are used to separate items and that no quotes are needed unless you are using a plotmath function name .... such as wanting the word "paste" or "sqrt" to appear in the displayed version of the expression.
Just paste them together:
expression(paste("A"[2], " and B"[2])
I wish to include a subscript and a title running into two lines at the same time but am not getting desired result with following commands:
base<-'B1'
compare<-'A1'
plot (1, 1, main = bquote('Annual mean' ~CO[2] ~'Flux Difference: \n' ~.(compare)~ 'minus'~.(base)))
I wish to insert a line break after 'Flux Difference' but its not happening instead this term is hanging nowhere. Please help me.
Thanks,
Munish
This is a fairly common request and there is no really clean answer. Plotmath will not accept a "\n" (and the help page documents this.) One dodge is to use each line as an argument to the plotmath function atop. The other plotmath trick sometimes of use is phantom with an empty argument list to allow the tilde not to throw an error, but that is not needed here:
plot (1, 1, main = bquote( atop('Annual mean' ~CO[2] ~'Flux Difference:' ,
.(compare)~ 'minus'~.(base))) )