Interactively zoom out on the current plot. Works on an existing
qmap object. Simply pass that object to zo(). A single zoom
out results and the extent of the qmap object is changed.
Usage
zo(qmap_obj = NULL, zoom_perc = 0.5, loc = NULL)
Arguments
qmap_obj
A qmap object. Optional, but performs better with larger
data sets.
zoom_perc
A proportion to determine the zoom level. The x and y
axes are increased by this amount. Default is 0.5.
loc
A list with an x and y numeric indicating a location. Default is
to interactively get loc value until escaped.