Taking as argument the list returned by the get.arcdata function, this function plots all the arcs. With the argument new the user can decide whether to plot on a new window/device or on the last window/device.
If the user provides the arguments 'xlim' and 'ylim' they will be used when calling the 'plot' function. Other way, the real boundary of the plotted arcs will be used.
plotarc(arc, new=TRUE, index=NULL, xlim, ylim, ...)