[R] variable values in plotmath expressions

[Gabor Grothendieck]

On Thu, Mar 15, 2012 at 10:25 PM, Richard M. Heiberger <rmh at temple.edu> wrote:
> ## I would like help in using variable values in plotmath expressions
> ## in lattice
>
> x <- 1:10
> y <- 1:10
> pval <- .95
>
> plot(y ~ x, ## works as I want in base graphics
>     main=substitute(list(alpha * " = " * group("",list(p),"")),
> list(p=pval)))
>
> plot(y ~ x, ## doesn't work as intended: "pval" is displayed
>     main=substitute(list(alpha * " = " * group("",list(pval),""))))
>
> try( ## doesn't work: object 'alpha' not found
> xyplot(y ~ x,
>     main=substitute(list(alpha * " = " * group("",list(p),"")),
> list(p=pval)))
> )
>
> xyplot(y ~ x, ## doesn't work as intended: "substitute" is displayed
>     main=expression(substitute(list(alpha * " = " * group("",list(p),"")),
> list(p=pval))))
>
> xyplot(y ~ x, ## doesn't work as intended: "p" is displayed and "pval" is
> displayed
>     main=expression(list(alpha * " = " * group("",list(p),"")),
> list(p=pval)))
>
> xyplot(y ~ x, ## doesn't work as intended: "pval" is displayed
>     main=expression(list(alpha * " = " * group("",list(pval),""))))

Try bquote with classic graphics or as.expression(bquote(...)) with lattice:

plot(y ~ x, main = bquote(alpha == .(pval)))

xyplot(y ~ x, main = as.expression(bquote(alpha  == group("", .(pval) ,""))))



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