COMMAND NAME:	xscale

TYPE:		Plot control

SYNTAX:		"xscale xmin xmax" (xmin, xmax floating point)

DESCRIPTION:

Sets the minimum and maximum X-axis values, overriding the
default, which is 0 to 360 degrees for phase quantities, or
the data range plus 10% at each end for other quantities.
Scale with no arguments restores the default.  When
the X-axis is multiband delay, the scale is automatically set
to +/- half the multiband delay ambiguity.
This can be overridden by an explicit "xscale" command.
If the axis is scantime, the "timerange" settings determine
the axis extrema.

Points which fall outside the scale limits are not plotted, and
a warning message is issued to alert the user as to how many
points were omitted.