fl - flag a location on the plot			Matthew Miller

EXAMPLES:

fl 3 ch:			draw line at channel 3
fl 115232 fr:			draw line at frequency 115232
fl 57 lt:0			draw dotted line at location 57 in
				whatever coordinates the current
				graph is plotted in
pl;cp;fl 0			draw a line at x=0 on a contour plot

DESCRIPTION:

Fl draws a vertical line on the current plot at a horizontal location given
in any type of units (channel, frequency, or velocity).  The default type of
unit is the current plot; thus, if the last plot was made in velocity, fl will
interpret the given horizontal location as a velocity.  Different units may be
used by using 'ch' (channels), 'fr' (frequency), or 'vl' (velocity).

As a side effect, fl will also draw a line on a contour plot if a spectrum was 
recently plotted.

The line may be drawn in any line type by setting 'lt' to the number of the
desired type.  The default value is 9 (thin solid line).  The range of line
types is 0 to 255.  The actual line type depends on the device.  Values
between 0 and 99 are coded by the two digits.  The ten's digit controls the
thickness or color with 0 thin and 9 thick.  The units digit controls
the dottedness with 0 most dotted and 9 solid.  Special line types are:
200 - the border of a plot,  201 - ticks on the border, 202 - the grid line with
zero value, and 203 - all other grid lines.  Line type 255 will be suitable 
for plotting data.

This document was last updated on Tue Oct 17 16:24:05 EDT 2000 by Marc W. Pound.