[Rd] Wishlist: strwidth allow for rotation of text (PR#7931)

[epurdom@stanford.edu]

Hi,

This is not a bug, but an enhancement suggestion. "strwidth" only gives the 
width of the text according to the x-axis user coordinates, and similarly 
for "strheight". Even if the par setting "srt" is changed to rotate the 
text, the resulting width (resp. height) is in terms of the non-rotated 
text. Currently, if I want to know how much space to leave for vertical 
text in the user coordinates, I manually invert the user coordinates, and 
then change them back.

Even if arbitrary "srt" is too much, just having the option for 90 degree 
rotation would be helpful. If it were implemented for arbitrary srt, then I 
personally think it's x-axis and y-axis dimensions are of interest, and not 
the actual length of the rotated text.

I'm using R 2.1.0, Windows XP

Thanks,
Elizabeth Purdom

Example:
plot(1:100,seq(2,5,length=100), type="n")
par("usr")
# [1]  -2.96 103.96   1.88   5.12
strwidth("hello","user")
# [1] 7.613353
par(srt=90) #rotate 90 degrees
strwidth("hello","user") #still gives same width of text
# [1] 7.613353
par(usr=par("usr")[c(3,4,1,2)])
strwidth("hello","user")
# [1] 0.2307077