Stop parsing out zeros after decimals in ggplot2's annotate

Question

I need to annotate a location on a ggplot2 plot with a line that contains both a (real) greek letter and a number rounded to 2 decimal places. My problem arises because I want to display the decimal places even if they are both zero. Unfortunately, the parse = T setting in annotate converts the string "1.00" into "1". Here's a specific example:

alpha_num <- "1.00"
p <- ggplot(data.frame(x=1,y=1,label=paste0("alpha == ", alpha_num)))
p <- p + geom_text(aes(x,y,label=label), parse = TRUE, size = 30)

The code above produces the following plot:

How do I get alpha_num displayed in its entirety?

Answer 1

You can do it with the use of deparse.

So your code looks like this

alpha_num <- "1.00"
p <- ggplot(data.frame(x=1,y=1,label=paste0("alpha == ", alpha_num)))
# Use deparse in label
p <- p + geom_text(aes(x,y,label=paste0("alpha == ", deparse(alpha_num))), parse = TRUE, size = 30)
p  

And the output is: