How to customise axes labels in ggplot2 from a list of string inputs?

Question

I am generating a bunch of plots and have stored the appropriate labels for axes in my plots in a list:

labels_list <- c("C[max,1] (mg/L)", "AUC[ 6wks,1 ] (mg*day/L)", "somethingElse[subscriptText] (units*might/have*symbols)")

My goal is to create labels where the text in the square brackets are subscripts. I have been using parse() which is okay, except:

• I can't figure out how to get the axes labels to be bold, though it is specified in my custom ggplot theme
• The asterisk disappears.

I know that bquote() is an option, but I haven't figured out how to use it if I just want to provide a list of strings as inputs like above. I'm definitely open to any suggestions and solutions provided.

EDIT: It seems that I cannot use my string inputs as-is? labels_list is extracted from a data frame and I would love to not have to, one-by-one, change this for plotting purposes. :-(

Answer 1

Here's an approach with expression and bold :

labels_list <- c(expression(bold(C[max * ',' * 1]~(mg/L))), 
                  expression(bold(AUC["6wks"*','*1]~(mg * '*' * day/L))),
                  expression(bold(somethingElse[subscriptText]~(units * '*' * might/have * '*' *symbols))))

ggplot(data = data.frame(x = 1, y = 1), aes(x,y)) +
  geom_point() + 
  labs(x = labels_list[1], y = labels_list[2], caption = labels_list[3])