How to draw a line or add a text outside of the plot area in R?

Thank you for reading. I find that I am unable to draw lines/points or add text outside of the plot area. If I draw a line from inside the plot (within the axis) area to the area of the xlab main titl开发者_开发百科e areas only the part within the plot shows. In a multiple plot graph (mfrow) the line/point will only be drawn inside the last active plot.

plot(0);
l=locator(2,type='n');
lines(l, type='l'); 

Any solution to this problem? Thanks!

The xpd parameter controls where you can draw. Check the current value with par()$xpd and then try setting par(xpd=NA).

From the par help:

 ‘xpd’ A logical value or ‘NA’.  If ‘FALSE’, all plotting is
      clipped to the plot region, if ‘TRUE’, all plotting is
      clipped to the figure region, and if ‘NA’, all plotting is
      clipped to the device region. See also ‘clip’.