Question

I have a data frame with numbers resembling:

df$X1    df$X2

.9     1.442

How could I use elements from this data frame to create labels for a confidence intervals that will be nicely formatted string:

(0.90, 1.42)

I’m lost somewhere between paste, as.character and c() and nothing seems to work :/

Answer 1

How about something like:

paste("(",df$X1,",",df$X2,")",sep="")

In your example, it looks like you might want to round your numbers, but the rounding is incorrect. Do you want a certain number of digits after the decimal point?

Also, “1” and “2” are frowned upon as names in a data.frame – see ?make.names

EDIT:

To round in cases like this, I like using formatC():

paste("(", formatC(df$X1, digits = 2, format = "f"), ",",
  formatC(df$X2, digits = 2, format = "f"), ")", sep = "")

However, if there are values less than .005, note that they will end up being 0.00.