Thank you for your suggestions. So you’re suggesting I bypass the ggplot symbol parsing by passing a character string to caption which has latex2exp in it. Good idea. So in this approach, I should break the string into new lines via ‘atop’? Thanks
From: Bert Gunter <bgunter.4...@gmail.com> Sent: Thursday, February 18, 2021 1:47 PM To: Izmirlian, Grant (NIH/NCI) [E] <izmir...@mail.nih.gov> Cc: r-help@r-project.org Subject: Re: [R] New line in caption with math symbols embedded in expression (paste( See also this: https://cran.r-project.org/web/packages/latex2exp/vignettes/using-latex2exp.html Bert On Thu, Feb 18, 2021 at 10:42 AM Bert Gunter <bgunter.4...@gmail.com<mailto:bgunter.4...@gmail.com>> wrote: Note, from ?plotmath: "Control characters (e.g., \n) are not interpreted in character strings in plotmath, unlike normal plotting." For this reason, as best I can tell, you need to fool with plotmath's "atop" command or do separate "labs" calls. This post seems to confirm that opinion: https://stackoverflow.com/questions/29112697/adding-a-newline-in-a-substitute-expression I certainly would welcome a better alternative. Cheers, Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Thu, Feb 18, 2021 at 9:37 AM Izmirlian, Grant (NIH/NCI) [E] via R-help <r-help@r-project.org<mailto:r-help@r-project.org>> wrote: ## I am using ggplot and trying to produce a caption containing math symbols. I need to ## add a second line. I did a fair amount of googling for answers. This one seemed like ## it would answer my question as it is nearly exactly my problem, except there is only ## one argument to the paste function. Note that my example is a complete minimal ## example, just a scatterplot with a line, and the caption content seems to not have ## anything to do with the plot. That is of course, intentional. ## ## https://stackoverflow.com/questions/13223846/ggplot2-two-line-label-with-expression library(ggplot2) X <- 10*runif(100) Y <- 2*X + rnorm(100, sd=2) fit <- lm(Y~X) Y.p <- predict(fit, newdata=data.frame(X=X)) DAT <- data.frame(X=X) ## without a newline p <- ggplot(data=DAT, aes(x=X)) + geom_point(aes(y=Y)) + geom_line(aes(y=Y.p)) p <- p + labs(caption=expression(paste(P,"(",FDP,">", alpha,") ", "for 'FDR' and 'Auto' FDP control method, vs '", m, "' at levels of 'eff size' (col) and '", p[1], "' (row)"))) p <- p + theme(plot.caption = element_text(hjust = 0)) ## newline, method 1, just add a new component of paste containing "\n" somewhere in the middle p <- ggplot(data=DAT, aes(x=X)) + geom_point(aes(y=Y)) + geom_line(aes(y=Y.p)) p <- p + labs(caption=expression(paste(P,"(",FDP,">", alpha,") ", "for 'FDR' and 'Auto' FDP control method, vs '", m, "' at levels of 'eff size' (col) and '", p[1], "' (row)", "and \n a new line"))) p <- p + theme(plot.caption = element_text(hjust = 0)) ## doesn't work because the newline affects only the last component of paste. It looks like new line ## works if the line is long enough, but the newline character is being parsed until the individual ## arguments to paste are parsed for math symbols but prior to pasting the components together. prior ## to pasting all arguments. I can't imagine why this would be the desired behavior. When the value of a ## caption argument is expression(paste(s1, s2, s3, ...)) then parsing for a newline character should ## occur after the components are pasted together, right? ## newline, method 2, enclose paste in another paste and add the new line as the second argument of the ## outer paste p <- ggplot(data=DAT, aes(x=X)) + geom_point(aes(y=Y)) + geom_line(aes(y=Y.p)) p <- p + labs(caption=expression(paste(paste(P,"(",FDP,">", alpha,") ", "for 'FDR' and 'Auto' FDP control method, vs '", m, "' at levels of 'eff size' (col) and '", p[1], "' (row)"), "and \n a new line"))) p <- p + theme(plot.caption = element_text(hjust = 0)) ## which has the same behavior [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org<mailto:R-help@r-project.org> mailing list -- To UNSUBSCRIBE and more, see 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. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
