R help - Jul 2010 - square brackets in expression in plots

Dears,


do you know whether it is possible to include any square parantheses (brackets)
in an expression to use it as an axis label?

e.g. I would like to have a label like (with the sub and superscripts correct):

"speed [m s^-1]"

I know how to combine an expression with text via paste, but as I run soimething
like:

a='m*s^{-1}'
plot(1:10,main=parse(text=a))

I found now way of doing this. I use the parse thing as I have all these units
stored as strings that represent expressions.


Cheers for any help!

Jannis

On Jul 20, 2010, at 12:42 PM, Jannis wrote:
> Dears,
>
>
> do you know whether it is possible to include any square parantheses  
> (brackets) in an expression to use it as an axis label?
>
> e.g. I would like to have a label like (with the sub and  
> superscripts correct):
>
> "speed [m s^-1]"
Not exactly clear what you mean by "correct".
>
> I know how to combine an expression with text via paste, but as I  
> run soimething like:
>
> a='m*s^{-1}'
> plot(1:10,main=parse(text=a))
?plotmath

This seemed to work fine with main, sub and xlab:

a='speed [m*s^-1]'
  plot(1:10,main=parse(text=a))

But maybe you wanted the square-brackets?

a='speed~bgroup("[", m*s^-1, "]")'
plot(1:10,main=parse(text=a))
>
> I found now way of doing this. I use the parse thing as I have all  
> these units stored as strings that represent expressions.
>
>
> Cheers for any help!
>
> Jannis
>
>
>
> ______________________________________________
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David Winsemius, MD
West Hartford, CT

On 20/07/2010 12:42 PM, Jannis wrote:
> Dears,
>
>
> do you know whether it is possible to include any square parantheses
(brackets) in an expression to use it as an axis label?
>
> e.g. I would like to have a label like (with the sub and superscripts
correct):
>
> "speed [m s^-1]"
>
> I know how to combine an expression with text via paste, but as I run
soimething like:
>
> a='m*s^{-1}'
> plot(1:10,main=parse(text=a))
>
> I found now way of doing this. I use the parse thing as I have all these
units stored as strings that represent expressions.
>
>   
plot(1,1, main=expression(paste("speed [", m * s^{-1},
"]")))

Duncan Murdoch