R help - Jun 2006 - text bubble (rectangle)?

Dear R wizards:  sorry to bug everyone twice in one day.

I would like to annotate my graph by putting text strings into
rectangle boxes with a little cartoon-like bubble with a lid pointing
to a specific location.  I can draw some sort of bubble-with-lid using
the R primitives.  (has anyone done something like this already?)

the problem where I am stuck is that the width of the rectangle must
depend on the length and font of my string.  is there a way to obtain
the lower left and upper right location of a text string that R drew?
(this would be good return values for the text() function, wouldn't
it?)

  bubble.annotate <- function( x, y, xlid, ylid, textstring ) { HELP }
  bubble.annotate( 19871010, 20, 19871019, 13, "Black Monday" );

[and thanks, gabor, for explaining the ifelse tricks with dates to me.]

regards,

/iaw

"ivo welch" <ivowel at gmail.com> writes:
> Dear R wizards:  sorry to bug everyone twice in one day.
> 
> I would like to annotate my graph by putting text strings into
> rectangle boxes with a little cartoon-like bubble with a lid pointing
> to a specific location.  I can draw some sort of bubble-with-lid using
> the R primitives.  (has anyone done something like this already?)
> 
> the problem where I am stuck is that the width of the rectangle must
> depend on the length and font of my string.  is there a way to obtain
> the lower left and upper right location of a text string that R drew?
> (this would be good return values for the text() function, wouldn't
> it?)
> 
>   bubble.annotate <- function( x, y, xlid, ylid, textstring ) { HELP }
>   bubble.annotate( 19871010, 20, 19871019, 13, "Black Monday" );
> 
> [and thanks, gabor, for explaining the ifelse tricks with dates to me.]
Have a look at strwidth/strheight.

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