par_org <- par(ask=TRUE) 
library(grid)
pg <- bezierArrowSmpl(x=c(.2, .5, .5, .8),
                y=c(.2, .2, .8, .8),
                width=unit(6, "mm"),
                arrow = list(base=unit(.1, "npc"),
                  length = unit(.1, "npc")))
              
plot.new()
grid.draw(pg)

plot.new()
pg <- bezierArrowSmpl(x=c(.2,.2,.8,.3),
  y=c(.3,.9,.8,.2))
grid.draw(pg)

plot.new()
pg <- bezierArrowSmpl(x=c(.3,.7,-.1,.25),
  y=c(.5,.1,.1,.5),
  align_2_axis = FALSE)
grid.draw(pg)
par(par_org) 
