Try using the I() function in the call to data.frame. E.g.,
> d <- data.frame(X=1:3, Y=1:3, Substance=I(expression(H[2]*O, H[2] * O[2],
H*S*O[4])))
> with(d, {plot(X,Y,type="n",xlim=c(0,4)); text(X, Y, Substance)})
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Sat, Mar 21, 2020 at 1:45 AM Troels Ring <tr...@gvdnet.dk> wrote:
> Dear friends - I have some old data of chemical results and want to
> annotate
> the points with chemical formula. If I just do
>
> ID <- c("HCl 7","HCl 5.25","HCl 3.5","HCL 7 no Na","HCl 3.5 No Na",
>
> "HSO4 7 no Na",
>
> "HNO3 7 No Na")
>
> I can make a data.frame like
>
> DD <- data.frame(x=1:7,ID)
>
>
>
> and plotting works fine.
>
> But if I try to format sulfuric acid and nitric acid like
>
> ID <- c("HCl 7","HCl 5.25","HCl 3.5","HCL 7 no Na","HCl 3.5 No Na",
>
> expression(paste(HSO[4]," 7 no Na")),
>
> expression(paste(HNO[3]," 7 No Na")))
>
>
>
> DD <- data.frame(x=1:7,ID)
>
> Elicits an error
>
> Error in as.data.frame.default(x[[i]], optional = TRUE) :
>
> cannot coerce class '"expression"' to a data.frame
>
> and plotting is prohibited - so how is this bypassed?
>
>
>
> I'm on Windows 10,
>
> R version 3.6.1 (2019-07-05)
>
>
>
> All best wishes
>
> Troels Ring, MD
>
> Aalborg, Denmark
>
>
> This email has been scanned by BullGuard antivirus protection.
> For more info visit www.bullguard.com
> <
> http://www.bullguard.com/tracking.aspx?affiliate=bullguard&buyaffiliate=smt
> p&url=/
> <http://www.bullguard.com/tracking.aspx?affiliate=bullguard&buyaffiliate=smtp&url=/>>
>
>
> [[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.
>
[[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.
