Re: [R] erasing an area of a graph

On 04/09/2010 04:51 AM, Terry Therneau wrote: I have a case where the easiest way to draw a particular symbol would be to draw something a little bigger, and then use polygon(... , col=0) to erase the extra stuff. Just how to do this best when par('bg') = 'transparent' is, however, eluding me.

Re: [R] erasing an area of a graph

I don't think this is possible. With an opaque background you can get back the background color just by overwriting, but any additional painting can only increase the opacity so you can't get back to transparent. -thomas On Thu, 8 Apr 2010, Terry Therneau wrote: I have a case where th

[R] erasing an area of a graph

I have a case where the easiest way to draw a particular symbol would be to draw something a little bigger, and then use polygon(... , col=0) to erase the extra stuff. Just how to do this best when par('bg') = 'transparent' is, however, eluding me. I've looked through the archives and the book R