R help - May 2012 - Catenating strings involving plotmath symbols.

In the context in which I am actually working it is necessary for
me to build parts of a text string to place on a plot in two separate
stages.

The following toy example illustrates what I am trying to do:

L1 <- substitute(list(paste("Bias in ", gamma,", ")))
L2 <- substitute(list(beta==b0),list(b0=300))

plot(1:10,main=L1) # Works fine.
plot(1:10,main=L2) # Works fine.

But what I want is the catenation of the strings contained in L1 and L2.
I thought that I might just be able to catenate them using c(), as in

plot(1:10,main=c(L1,L2))

but this just gives me the "L1" title, and L2 gets ignored.

Is there any way to accomplish my goal?

(Please don't tell me how to build a single string to use as a title;
I know how to do that.  I need to be able to build two separate
strings and then combine them somehow.)

It seems to me that it should be do-able, but I have no idea where
or how to look for the appropriate incantation.  Googling around,
I found lots of stuff on how to catenate vectors or paste together
"ordinary" text strings, but nothing on how to catenate mathematical
expressions.

Can anyone help me out?

     cheers,

         Rolf Turner

Try this,

bquote(.(L1) * .(L2))

HTH,

b.

On 19 May 2012 16:17, Rolf Turner <rolf.turner at xtra.co.nz>
wrote:
>
> In the context in which I am actually working it is necessary for
> me to build parts of a text string to place on a plot in two separate
> stages.
>
> The following toy example illustrates what I am trying to do:
>
> L1 <- substitute(list(paste("Bias in ", gamma,",
")))
> L2 <- substitute(list(beta==b0),list(b0=300))
>
> plot(1:10,main=L1) # Works fine.
> plot(1:10,main=L2) # Works fine.
>
> But what I want is the catenation of the strings contained in L1 and L2.
> I thought that I might just be able to catenate them using c(), as in
>
> plot(1:10,main=c(L1,L2))
>
> but this just gives me the "L1" title, and L2 gets ignored.
>
> Is there any way to accomplish my goal?
>
> (Please don't tell me how to build a single string to use as a title;
> I know how to do that. ?I need to be able to build two separate
> strings and then combine them somehow.)
>
> It seems to me that it should be do-able, but I have no idea where
> or how to look for the appropriate incantation. ?Googling around,
> I found lots of stuff on how to catenate vectors or paste together
> "ordinary" text strings, but nothing on how to catenate
mathematical
> expressions.
>
> Can anyone help me out?
>
> ? ?cheers,
>
> ? ? ? ?Rolf Turner
>
> ______________________________________________
> 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.