[R] Help with expression()

Sheri O'Connor soconnor at lakeheadu.ca
Thu Oct 10 22:08:17 CEST 2013

Hi everyone,

I am hoping someone can help with my attempted use of the expression
function. I have a long series of text and variable to paste together
including a degree symbol. The text is to be placed on my scatter plot
using the mtext function.

Using expression like this:

changetext = expression(paste("Change from ",mini," to ", maxi, ":",
diff ,degree,"C",collapse=""))

does not evaluate my user defined variables - mini,maxi, and diff -
just printing them out as words

Using expression like this:

changetext = paste("Change from ",mini," to ", maxi, ":", diff

prints the text twice and does not evaluate the degree symbol.

I have tried to place the expression alone in a variable and then run the paste:

degsym = expression(degree,"C")
changetext = paste("Change from ",mini," to ", maxi, ":", diff

giving me the same result as the second option

Is there any way I can use the expression function as in the first
example but still have R evaluate my user defined variables?


Sheri O'Connor
M.Sc Candidate
Department of Biology
Lakehead University  - Thunder Bay/Orillia
500 University Avenue
Orillia, ON L3V 0B9

More information about the R-help mailing list