[R] Plotting a registered sign

[David Winsemius]

On Mar 1, 2012, at 2:40 PM, Dennis Fisher wrote:

> R 2.14.0
> OS X
>
> Marc's proposed solution (appearing at the end of this email) is  
> perfect -- thanks so much
> However, some questions remain:
>
> 1.  The following works:
> 	plot(1, type="n")
> 	text(1, 1, expression(symbol("\342")))
>
> but this does not work (TEXT appears in a symbol font)
> 	plot(1, type="n")
> 	TEXT	<- "\342"
> 	text(1, 1, expression(symbol(TEXT)))

?substitute
   text(1, 1, substitute( symbol(TEXT), list(TEXT=TEXT) )  )

?bquote

text(1, 1, bquote( symbol( .(TEXT )  ) ) )

>
> nor does this work (it yields:	Error: could not find function  
> "symbol")
> 	plot(1, type="n")
> 	TEXT	<- symbol("\342")
> 	text(1, 1, expression(TEXT))
> Clearly, I do not understand the subtleties of plotmath.

expression() does not evaluate names within its arguments. Similar  
issues arise with the use of "$" as a function. That's why it's often  
the answer to programming questions that one should use obj[[colnam]]  
than it is to use obj$colnam. "[[" does evaluate its argument.

>  Could someone explain?

Try instead:

plot(1, type="n")
	TEXT	<- expression(symbol("\342"))
	text(1, 1, TEXT)

If you want to build up from character-type components then you can  
use paste and wrap the whole think in as.expression(). bquote() is  
much better, though.

-- 
David.

>
> 2.  How would one learn that \342 corresponds to the copyright sign  
> in the symbol font? (i.e., is there a list of all possible characters)
>
>
>
> Dennis Fisher MD
> P < (The "P Less Than" Company)
> Phone: 1-866-PLessThan (1-866-753-7784)
> Fax: 1-866-PLessThan (1-866-753-7784)
> www.PLessThan.com
>
> On Feb 29, 2012, at 6:55 PM, Marc Schwartz wrote:
>
>> Dennis,
>>
>> Depending upon some additional fine tuning, here is a generic  
>> example:
>>
>> plot(1)
>> legend("topright", pch = 1, legend = expression(SOMETEXT ^  
>> symbol("\342")))
>>
>>
>> See ?plotmath for more information. The above works on my MBP  
>> running Lion.
>>
>> HTH,
>>
>> Marc Schwartz
>>
>
>
> 	[[alternative HTML version deleted]]
>
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David Winsemius, MD
West Hartford, CT