R help - Nov 2012 - vectorized plotmath expressions via substitute()

hi all - i've seen versions of this question before, but none seem to get
directly at my solving my (probably very simple) issue:

i simply want to annotate the tick marks on an axis with (superscripted)
10^x notation, and tried this:

axis(1, at = axTicks(1), as.expression(substitute(10^foo, list(foo axTicks(1))))

thinking the as.expression/substitute would create the appropriate
expression vector from the expansion of the foo vector.
i'm continually stuck in the error process, however, with axis() where R
complains that i've only provided a single label.
i must be missing a function that explicitly "unfolds"(?) the result
of the
substitute() call, without actually evaluating the contents of that call?

sorry in advance if this is clear in the docs somewhere, though i just
can't seem to locate it :-/

cheers and thanks for any pointers!

-murat

	[[alternative HTML version deleted]]

I recommend using bquote(), with its .() substitution operator, instead of
substitute any time you use plotmath.    To make a vector of plotmath
expressions use the following sort of as.expression(lapply(... bquote ...))
idiom:

  plot(1:10, axes=FALSE)
  at <- axTicks(1)
  lab <- as.expression(lapply(at, function(a)bquote(10^.(a))))
  axis(1, at=at, lab=lab)

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at
r-project.org] On Behalf
> Of Murat Tasan
> Sent: Wednesday, November 14, 2012 9:06 AM
> To: r-help at r-project.org
> Subject: [R] vectorized plotmath expressions via substitute()
> 
> hi all - i've seen versions of this question before, but none seem to
get
> directly at my solving my (probably very simple) issue:
> 
> i simply want to annotate the tick marks on an axis with (superscripted)
> 10^x notation, and tried this:
> 
> axis(1, at = axTicks(1), as.expression(substitute(10^foo, list(foo >
axTicks(1))))
> 
> thinking the as.expression/substitute would create the appropriate
> expression vector from the expansion of the foo vector.
> i'm continually stuck in the error process, however, with axis() where
R
> complains that i've only provided a single label.
> i must be missing a function that explicitly "unfolds"(?) the
result of the
> substitute() call, without actually evaluating the contents of that call?
> 
> sorry in advance if this is clear in the docs somewhere, though i just
> can't seem to locate it :-/
> 
> cheers and thanks for any pointers!
> 
> -murat
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

On Wed, Nov 14, 2012 at 12:05 PM, Murat Tasan <mmuurr at gmail.com>
wrote:
> hi all - i've seen versions of this question before, but none seem to
get
> directly at my solving my (probably very simple) issue:
>
> i simply want to annotate the tick marks on an axis with (superscripted)
> 10^x notation, and tried this:
>
> axis(1, at = axTicks(1), as.expression(substitute(10^foo, list(foo >
axTicks(1))))
>
> thinking the as.expression/substitute would create the appropriate
> expression vector from the expansion of the foo vector.
> i'm continually stuck in the error process, however, with axis() where
R
> complains that i've only provided a single label.
> i must be missing a function that explicitly "unfolds"(?) the
result of the
> substitute() call, without actually evaluating the contents of that call?
>
> sorry in advance if this is clear in the docs somewhere, though i just
> can't seem to locate it :-/
>

See

library(sfsmisc)
?eaxis

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