watermark_txt: Add a watermark text
Description
Add a watermark text
Usage
watermark_txt(txt, x, y, location = "br", rot = 0, ...)
Arguments
x
the x location of the watermark (0-1 scale)
y
the y location of the watermark (0-1 scale)
location
one of tr (top right), tl (top left), bl (bottom left), br (bottom right), center (view center)
...
arguments passed to grid::gpar() (e.g. alpha)