Re: Confusion with labels and viewports

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Gary,
You should be safe using XAXIS_MIN, XAXIS_MAX, YAXIS_MIN,
and XAXIS_MAX to locate labels in your plots, whether they're in viewports
or not.  These are defined as soon as a plot is made, so if you draw the 
plot,
you can then access them to place labels.

yes? use coads
yes? shade/i=1 sst
yes? label/user `(($xaxis_max)+($xaxis_min))/2`, `($yaxis_max)*1.1`, 0, 
0, .14, "Centered in T, above top axis"


The PPL$ symbols are all documented in the PPLUS Users Guide, which
is Appendix B to the Ferret Users Guide.  Take a look at AppendixB,
Sec 7.3, "General Global Symbols". 
The values of PPL$XMIN1, PPL$XMAX1 etc, are computed from the data,
so they are the min and max of the variables.  The Ferret axis ends are 
by default
computed from the data, and so should be related to the data extremes, 
rounded
up and down to get nice intervals of tics on the axes.

Ansley Manke


Gary Strand wrote:

> Suppose I have a plot that I'd like the labels I create (via 'LABEL' 
> command) to always be in the same place regardless of whether I change 
> the aspect ratio, or the viewport, or things like that. 'LABEL/NOUSER' 
> is too rigid for this purpose, since I usually end up with labels 
> drawn outside the plot itself, or in the middle, or somewhere else wrong.
>
> So, using 'SHOW SYMBOLS/ALL', I see a number of variables I could use, 
> including
>
> PPL$XMIN1, PPL$XMAX1, PPL$YMIN1, PPL$YMAX1,
> XAXIS_MIN, XAXIS_MAX, YAXIS_MIN, and $AXIS_MAX
>
> The *AXIS_M* ones make sense - for the time series data I'm plotting, 
> with a fixed vertical range (i.e., 'PLOT/VL=0:10:1'), the YAXIS values 
> are right what they should be. The XAXIS values are basically in the 
> units of the time axis, for example, since my time axis is specified 
> as 'days since 1979-01-01', XAXIS_MIN has a value of 722517, when 
> divided by 365, is ~1979. This also makes sense.
>
> However, the PPL$ values make no sense to me at all. In this example, 
> PPL$XMIN1 is 5.6928E+04, PPL$XMAX1 is 1.1169E+06. What "units" are those?
>
> I can experiment around with manipulating the X and Y positions of my 
> LABELs, until they miraculously end up where I want them, but that is 
> too trial-and-error to be efficient.
>
> Ideas would be most welcome.
>
> /\        Gary Strand (303) 497-1336                                
> NCAR ML220
>   \_][    www.cgd.ucar.edu/ccr/strandwg                     1850 Table 
> Mesa Dr
>       \___strandwg@ucar.edu                 Boulder, Colorado, USA  
> 80305-3000