[R] expression over-plotted

[Chris Campbell]

On Fri, Mar 26, 2010 at 16:05, Brad Eck <brad.eck at mail.utexas.edu> wrote:
>
>   When I try to add the following annotation to a plot the entries are plotted
>   one on top of the other.  I'm trying to get something that looks like " eta
>   =  0.2  "  where the Greek letter is used on the plot.  I realize that
>   expression( eta == 0.2) is one solution, but ultimately I'd like to use this
>   in a legend that uses a loop to fill the entries so I don't want the 0.2
>   entered manually.
>   val <- 0.2
>   plot( c(0,1), c(0,1) )
>   text(  0.5, 0.5, c( expression( eta ), paste( ' = ', val ) ) )
>   Thanks,
>   Brad
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Your text is a vector of length 2 and you are plotting each element
over the same x,y coordinates, hence the overlap.  You could either
add a second x-coordinate to spread things out:

text(  c(0.5,0.55), 0.5, c( expression( eta ), paste( ' = ', val ) ) )

or use bquote:

text(  0.5, 0.5, bquote(eta == .(val) ) )

Hope that helps