Re: [ferret_users] Use of legline.jnl on time axis

["William S. Kessler" <William.S.Kessler@xxxxxxxx>]

No trick. No easy way, either. There are 2 possibilities:

1. After having made the plot, do PPL LIST TAXIS. The output will look 
something like this:

yes? ppl list taxis

         TAXIS QUALITIES
         LO= 8.76E+03 DT= 6.00E+01 CSIZE= 1.00E-01 TYPE= TAXIS3 VANG= 
0.00E+00
          TOP AXIS= ON  BOTTOM AXIS= ON
           TMIN=19920101000000  0:00 JAN  1,1992
           TMAX=20030101000000  0:00 JAN  1,2003
         TSTART=19901231235724 23:57 DEC 31,1990
         NMTC= -1 LABEL= -3 IFDB=  3 ISDB=  1 TAXIS= XAXIS IAUTOT= ON

TMIN is the starting value of the plotted time axis. TSTART is the 
beginning of the time axis (not on the plot but somewhere in Ferret's 
mind). It is usually about 1 year earlier than TMIN, as shown here. All 
references to a location on the plot must be relative to TSTART, not 
TMIN. DT is the time unit Ferret is using, in minutes (here it is one 
hour).

Thus,, to make a legend line of length 1 year, beginning 1 year to the 
right of TMIN, do something like:

go legline.go `365*24*2` `365*24` [yvalue]  [line_type]  [char_ht]  
"this is the label to use"

2. In response to this cumbersome method, which cannot be automated 
because it requires the plot to be made and inspected, Emily Vanvyve 
figured out how to do a legend line in NOUSER units. The script 
converts NOUSER to USER units, then calls legline.go. It is not 
bullet-proof but often works. Here is the script:

\can mode verify
! make a legend line and its label (nouser units) (Vanvyve e-mails 25 
July 2003)
! still calls user-unit legline script, but pre-chooses to make nouser 
units

! arg1=x-value of line starting point (fraction of plot width)
! arg2=length of line (fraction of plot width)
! arg3=y-value of line (fraction of plot height)
! arg4=line type (number 1-19)
! arg5=text character height
! arg6=label text
! only gets label position right for positive-up axes

let xrange `($xaxis_max) - ($xaxis_min)`
let yrange `($yaxis_max) - (($yaxis_min))`
let leg1 `($xaxis_min) + xrange*$1`
let leg2 `xrange*$2`
let leg3 `($yaxis_min) + yrange*$3`

go legline.go `leg1` `leg2` `leg3` $4 $5 "$6"
set mode/last verify

Additional complications ensue when the vertical plot axis is down (a 
depth axis). Clearly Ferret needs a better legend line situation than 
these user kluges.

Billy K
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
William S. Kessler
NOAA / Pacific Marine Environmental Laboratory
7600 Sand Point Way NE
Seattle WA 98115 USA

william.s.kessler@noaa.gov
Tel: 206-526-6221
Fax: 206-526-6744
Home page: http://www.pmel.noaa.gov/~kessler


On Sep 28, 2005, at 4:11 AM, Paulo B. Oliveira wrote:

> Hi,
>
> What's the trick to make legline work with a time-series plot ?
> Here is a test script and the results to illustrate the problem:
> ------------------------------------------------------------
> def ax/t=1-jan-2005:21-feb-2005:1/unit=day t1
> set win/asp=0.5
> set viewp left
> plot/i=1:10 i
> go legline 1 5 5 2 0.2 LAB1
> set view right
> plot t[gt=t1]
> go legline `t[gt=t1,t=1-jan-2005]` 5 37990 2 0.2 LAB1
> frame/file=legline_test.gif
> ------------------------------------------------------------
>
> Best regards,
> Paulo
> <legline_test.gif> ! NOAA/PMEL TMAP
>  ! FERRET v5.81
>  ! Linux(g77) 2.4.21-32 - 07/13/05
>  ! 27-Sep-05 19:57
>
> def ax/t=1-jan-2005:21-feb-2005:1/unit=day t1
>
> set win/asp=0.5
>
> set viewp left
>  plot/i=1:10 i
>  go legline 1 5 5 2 0.2 LAB1
>
> set view right
>  plot t[gt=t1]
>  go legline `t[gt=t1,t=1-jan-2005]` 5 37990 2 0.2 LAB1
>
> frame/file=legline_test.gif
>
> quit