clickbox(add=TRUE, ...)add=FALSE) or draw over the existing plot (add=TRUE).
polygon to plot the
box.
"owin") representing the
selected rectangle.
The user is prompted to point the mouse at any desired locations for two corners of the rectangle, and click the left mouse button to add each point.
The return value is a window (object of class "owin")
representing the rectangle.
This function uses the R command locator to
input the mouse clicks. It only works on screen devices such as
X11, windows and quartz.
clickpoly,
clickppp,
clickdist,
locator