R help - Aug 2012 - Plot label axis with expression

Hi all,

I need help with axis in plot.

I want to edit y axis label of my plot. My data is like:

x <- c(100,50,10,1,0.1,0.05,0.001)

plot(log(x))

axTicks(2) # Label of y axis
[1] -6 -4 -2  0  2  4

I'd like that y axis label was like: e^-6, e^-4, etc. (with text
"e"
superscript -6, -4, etc.) I try to use expression(), but don't work.

plot(log(x), yaxt="n")
axis(2, at=axTicks(2),
labels=expression(rep("e",times=length(axTicks(2))) ^
axTicks(2)), las=2)

Anybody have idea how to do this?

Regards,

MJ
...................................................
Mario Jos? Marques
Master student in Ecology
Institute of Biology, Dept. Plant Biology, Ecology Lab.
State University of Campinas - UNICAMP
Campinas, S?o Paulo, Brazil 



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Hello,

Use 'parse' for converting from character to expression:

x <- c(100, 50, 10, 1, 0.1, 0.05, 0.001)
plot(log(x), yaxt = "n")

parse(text = sprintf("e^%d", axTicks(2)))
## expression(e^-6, e^-4, e^-2, e^0, e^2, e^4)

axis(2, at = axTicks(2), labels = parse(text = sprintf("e^%d",
axTicks(2))), las = 1)

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Noia Raindrops
noia.raindrops at gmail.com