I'm trying to label a plot in R with superscript. For example, I have a variable called label:
>label <- colnames(tmp.df);
>label
[1] "ColumnA" "Volume 100mm3", "ColumnC", etc.
I would like to have "3" in the "Volume 100mm3" as superscript in my plot label. I cannot use something like:
label <- c("ColumnA", expression(paste('Volume 100mm'^'3')), "ColumnC");
since the ordering of the column names in tmp.df may change from run to run. So how can I get around this problem?
You could find the one with the mm by
ind <- grep("mm",label)
splt <- strsplit(label[ind], "mm")[[1]]
and then inject the expression via
label[ind] <- parse(text=sprintf("paste('%smm'^'%s')",splt[1],splt[2]))
If there are multiple strings that indicate the need for expressions, then it should be straightforward to adapt this.
You can use bquote for this. The * connects "Volume 100" to "mm^3" without a space. If you want a space there, you can use ~ instead of *.
plot(1:10, main = bquote(.("Volume 100") * mm^3))
how about just using the Unicode character for cubed 'SUPERSCRIPT THREE' (U+00B3)? in R, this would be escaped as '100mm\u00B3', or if this is coming from a data file, just use unicode characters directly in the file.
