Re: labelling ...

[Mick Spillane <spillane@xxxxxxxxxxxxx>]

Hi Emilie,
	Welcome to Ferret! Most of what you want can be achieved - but at
the cost of increased customization if the wants are not among the built-in
style choices.

1) the legends for the different curves
> My first question is : Is it possible to put this legend somewhere else ?
> Because it is not so well visible there and the text size is too small.
> (a sub-question is : is it possible to put the 4 filenames in this
> legend ? Because there are just 3 ... The first data filename is not
> there, it is in the "data set" above-right).
I think you probably plotted the variable from file#1 first, then added
the other 3 as overlays.  A more pleasing result may result if you plot
all 4 with a single command, as in the following demo

def axis/t="1-dec-2002:00:00":"31-dec-2002:18:00":6/units=hours tax
def grid/t=tax grd ; let tt=l[g=grd]
let/title="T (dataset-1)" v1=tt
let/title="T (dataset-2)" v2=125-tt
let/title="T (dataset-3)" v3=125-2*(tt-64)
let/title="T (dataset-4)" v4=2*(tt-64)
! this gives me 4 variables with names of my choosing.
plot v1,v2,v3,v4

Introducing new variables like that
          let/title="T (dataset-1)" v1=t321[d=1]
helps to reduce the length of the default string for a dataset variable.
When plotted together the default appearance is not too bad. But if you
want to make changes you can do so in various ways.

a) if the position of the line samples is acceptable but the size of
   text is too small - use "ppl listsym" to identify the labels in
   question (5,6,7,8) and increase height
ppl hlabs,5,0.2 ; ppl hlabs,6,0.2 ; ppl hlabs,7,0.2 ; ppl hlabs,8,0.2
ppl plot

b) The placement of the sample lines can be controlled by turning them
   off (plot/nolab) then adding them with a set of ppl aline commands.
   But the placement of the sample line text can be customized by making
   them movable and positioning them using crosshairs. For the latter
ppl labs,5,@p1@crDataset-1 ; ppl labs,6,@p2@crDataset-2
ppl labs,7,@p3@crDataset-3 ; ppl labs,8,@p4@crDataset-4
ppl plot
!where I've changed the font and color of the labels and you can place the
them wherever you want - maybe with arrows associating ech with its curve.
A dialog box opens on the plot for each movable label - first click on the
label style, then place the crosshair where the lable should appear and
click again. Maybe you could dispence with the sample lines entirely and
use colored text strings within the box, perhaps as follows
plot/set/nolab v1,v2,v3,v4
ppl txlint,1,0 ; ppl plot ! which starts with labeled axes only
                          ! and removes the DEC below the days
label/nouser 4 -0.5 0 0 0.15 @crDecember 2002
label/nouser 7.9 1.00 1 0 0.15 @p1@crDataset-1
label/nouser 7.9 0.75 1 0 0.15 @p2@crDataset-2
label/nouser 7.9 0.50 1 0 0.15 @p3@crDataset-3
label/nouser 7.9 0.25 1 0 0.15 @p4@crDataset-4

2) Time axis labelling
> My second question is : How can I put my t-axis in a format like
> DD-MMM-YYYY ?
This is not among the labelling choices available so if you really
want it you will have to customize it entirely by first turning off
time axis labelling ...
plot/set/nolab v1,v2,v3,v4 ; ppl txlabp,0 ; ppl plot
... then positioning labels at selected axis precalculated axis positions
using label/nouser
label/nouser 0.1 -0.3 0 0 0.1 @sr1-DEC-2002
label/nouser 7.9 -0.3 0 0 0.1 @sr31-DEC-2002
label/nouser 3.9 -0.3 0 0 0.1 @sr15-DEC-2002
! or as movable labels with crosshair positioning
ppl labs,1,@sr01-DEC-2002
ppl labs,2,@sr06-DEC-2002
ppl labs,3,@sr11-DEC-2002
ppl labs,4,@sr16-DEC-2002
ppl labs,5,@sr21-DEC-2002
ppl labs,6,@sr26-DEC-2002
ppl labs,7,@sr31-DEC-2002
ppl plot

Positioning custom labels is a lot easier in non-timeaxis situations
maybe with the use of a repeat/i=... (label ...) construction. Note that
when you use movable labels your choices are written to a file (fort.41)
which you can incorporate into future scripts with the same axis.

--------------------------------------------------------------------
The purpose of this lengthy reply was to demonstrate that just about
anything can be achieved with sufficient effort at customization. To
learn the tools, and know the built-in choices, you will need to digest
the PlotPlus Users Guide
   ftp://ftp.pmel.noaa.gov/epic/manual-dir/pplus.pdf
and the PPL+ extensions
   http://ferret.wrc.noaa.gov/Ferret/Documentation/PPLUS_Users_Guide/
                                         pplus_enhance_user_guide.html

Good luck,
Mick