Re: hlim and vlim qualifiers with time plot

[Mick Spillane <spillane@xxxxxxxxxxxxx>]

Hi Patrick,
	I think there must be two versions of the time axis involved when
the time axis is in "calendar" mode.  If you look at the results of "show
symbols" you will see them both
	XAXIS_MIN = "10000.000" , XAXIS_MAX = "120000.0"
are in terms of the dataset units of hours and the limits you imposed,
but the other is seen in
	PPL$XFIRST1 = "1.6657E+07" , PPL$XLAST1 = "1.6767E+07".

For some purposes (such as aline) is is the latter scale you need -
	ppl aline,1,1.6657E+07,-1,1.6767E+07,1
would give you the diagonal you need.  Another way would be to use
	plot/o/vs/nolab/line=2 {10000,120000},{-1,1}

By the way for calendar axis the "ppl time" command may be of use in
forcing the axis to begin and end on a year tic

 use monthly_navy_winds
 plot/vlim=-1:1/set UWND[i=@ave,j=@ave]
 ppl taxis,W198101010000,W199401010000 ; ppl plot

The start and end times are set in "Woods Hole" format WYYYYMMDDhhmm
If the default month/year axis labelling are not to your liking you
can customize them with the "ppl txlint" command
 ppl txlint,0,2 ; ppl plot

Hope this is of some help,
Mick

PS For more on PlotPlus commands see the Users Guide in HTML at
	http://www.epic.noaa.gov/epic/software/pplus_html/title.html
or in PDF at
	ftp://ftp.epic.noaa.gov/epic/manual-dir/pplus.pdf

The PPL+ document on "Ferret-specific PPLUS enhancements" can be accessed
via the Ferret Documentation page
	http://ferret.wrc.noaa.gov/Ferret/Documentation/