[R] plotmath and logical operators?

[Gabor Grothendieck]

Try this:

plot(1)
tmp <- x >= 3 ~ "&" ~ y <= 3
mtext(tmp)
On Mon, Aug 20, 2018 at 5:00 PM MacQueen, Don via R-help
<r-help using r-project.org> wrote:
>
> I would like to use plotmath to annotate a plot with an expression that includes a logical operator.
>
> ## works well
> tmp <- expression(x >= 3)
> plot(1)
> mtext(tmp)
>
> ## not so well
> tmp <- expression(x >= 3 &  y <= 3)
> plot(1)
> mtext(tmp)
>
> Although the text that's displayed makes sense, it won't be obvious to my non-mathematical audience.
>
> I'd appreciate suggestions.
>
>
> I've found a work-around that gets the annotation to look right
>   tmpw <- expression(paste( x >= 3, " & ", y <= 3) )
>   plot(1)
>   mtext(tmpw)
>
>
> But it breaks my original purpose, illustrated by this example:
>
> df <- data.frame(x=1:5, y=1:5)
> tmp <- expression(x >= 3 & y <= 3)
> tmpw <- expression(paste( x >= 3, " & ", y <= 3) )
> with(df, eval(tmp))
> [1] FALSE FALSE  TRUE FALSE FALSE
> with(df, eval(tmpw))
> [1] "FALSE  &  TRUE" "FALSE  &  TRUE" "TRUE  &  TRUE"  "TRUE  &  FALSE" "TRUE  &  FALSE"
>
> Thanks
> -Don
>
> --
> Don MacQueen
> Lawrence Livermore National Laboratory
> 7000 East Ave., L-627
> Livermore, CA 94550
> 925-423-1062
> Lab cell 925-724-7509
>
>
>
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