Re: Time Axis Labels

[verschel@xxxxxxxxxxxxxxxxxxxxx (Mark A. Verschell)]

The time axis is a separate deal from the x-axis and y-axis commands. To modify
the time axis you use the following commands:

TXLABP        establishes time axis label position (or absence)
TXTYPE*       sets the style of the time axis
TXLINT*       specifies which time axis tics will be labeled
TXLSZE        sets height of time axis labels
TXNMTC        sets number of small tics between large tics on time axis

>From the PPLUS manual:

     TXLABP,n

               Specifies time axis label position (-1 for below  plot,
          0 for no label, or +1 for above plot).


     TXLINT,low_int,hi_int

               Specifies which time axis tics will be labeled.

          Low_int = labeling interval for lowest level of tics
                    (e.g. mon on mon/yr axis)
          Hi_int = labeling interval for highest level of tics
                    (e.g. yr on mon/yr axis)


     TXLSZE,ht

               Specifies height of time axis labels (inches).


     TXNMTC,n

               Specifies number of small tics between  large  tics  on
          time  axis.   If NMTCT is -1 the major divisions are denoted
          by large  tics  and  the  minor  divisions  by  small  tics,
          otherwise  they  are  denoted  by thick tics and large tics,
          respectively.


     TXTYPE,type,style

               Specifies type and style of time series axis.
          type = DAYS
                        style = HR (hour,day on 2 lines) (default)
                                HRDAY (on 1 line)

               = MON
                        style = DAY (day,mon on 2 lines) (default)
                                DAYMON (day,mon on 1 line)

               = YR (default)
                        style = MON1 (1-char month)
                                MON3 (3-char month) (default)
                                MONYR (month,yr on 1 line)

So, to eliminate the year on your time axis:

PPLUS TXTYPE,YR,MON3           ! For example
PPLUS TXLINT,0,1               ! Print no years but display every month label

As for the user coordinates in the label command, yes there is some
"difficulty" in using user coordinates with a time axis. Ferret stores the time
axis as a time step, and these depend on T0 (initial time that defines the
axis), and the units. If you are using hours as your units the time steps can
be large.

Instead, use the interactive labeling facility to help in placement. Do your
normal plotting command with the /SET qualifier, then do the labels as PPLUS
commands:

PPLUS LABS,1,,,,"My Label"    ! No values for X, Y, or JST

then
PPLUS (your plotting command)

For every PPLUS LABS command without X,Y,JST being explicitly entered, you
bring up an interactive plotting window. Click on one of the menu choices, and
then click on your plot where you want the label to go. If you click on one of
the two line options, the first click places the tail of the line, then you get
another window to choose the justification of your label (which will be at the
head of the line).

To set this up for batch processing, ferret writes all the label commands in
the file fort.41 - with the interactively selected coordinates. These label
commands can be modified or adjusted and then placed in a .jnl file.

Hope this helps, Mark

On May 11,  6:36pm, nils rix wrote:
> Subject: Time Axis Labels
>
> Dear ferreters,
> I'm trying to customize a time-latitude contour plot. Say I have
> a monthly time axis for a specific year, then ferret
> writes abbreviations of the months onto the axis and the
> year below it. I'd like to change or omit the year (and maybe the monthly)
> label. Attempts to do this with "ppl xlab .." fail though.
> I have similar problems using
> user coordinates with the label command and can't figure out how they
> need to be specified. Seems like using a time axis as an x/y-axis needs
> to be treated as in a special way.
> Does anybody have a clue and knows how this can be done?


-- 
 Mark Verschell                     NASA/Goddard Space Flight Center
 verschell@neptune.gsfc.nasa.gov    Code 970/Lab. for Hydrospheric Proc.
 301-286-2027  Fax: 301-286-1761    Greenbelt, MD 20771