Re: How to customize the ascii output format?

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

Hi Ding,
I see there is a parallel discussion on this topic in the LAS users list;
one solution is to use the customization options ther.  One could also
use tools like perl to read and reformat the headers after Ferret lists
the data.  These could be called from a Ferret script with spawn
commands.

In Ferret, you can certainly output the ASCII data without a header,
with the LIST/NOHEADER qualifier. A different header is written with
LIST/HEADING=ENHANCED.  Ferret does not have much ability
to customize the header beyond that. You could make your own header
with a set of SPAWN commands, with or without the automatically-
generated header.

yes? SPAWN echo "first header line" > a.dat
yes? SPAWN echo "second header line" >> a.dat
yes? LIST/APPEND?FILE=a.dat   var

We might think of adding qualifiers LIST/PRE=   and LIST/COMMENT=
to let the user add text before and after the Ferret header; these could
be called with /NOHEADER to write an entirely  custom header.

Ansley

Ansley Manke

Chi Ding wrote:

>  Hi everybody
>         I'm using ferret to extract ascii data out of my netcdf file
> upon x/y/z/t selected by users.
>        The ferret statements are like
>        REPEAT/l=($lmin):($lmax):`lchunk` 
> REPEAT/k=($kmin):($kmax):`kchunk` REPEAT/j=($jmin):($jmax):`jchunk` 
> (list/append/file($format)/j=`j`:`jtop`/k=`k`:`ktop`/l=`l`:`ltop` 
> ($theVar); CANC MEM/ALL)
>        And the output  format is like
>        VARIABLE : WIND_SPEED (m/second)
>            FILENAME : sb3.nc
>            FILEPATH : /home/local/ferret/go/
>            BAD FLAG :  -99999.00                SUBSET   : 145 points 
> (TIME)
>            LONGITUDE: 30W
>            LATITUDE : 40N
>            Z (meters): 0
> coordinates    30W  28-SEP-2003 00    6.919
> 28-SEP-2003 01    7.104
> 28-SEP-2003 02    7.295
> 28-SEP-2003 03    7.928
> 28-SEP-2003 04    7.701
> 28-SEP-2003 05    8.061
> 28-SEP-2003 06    7.856
> 28-SEP-2003 07    8.169
> 28-SEP-2003 08    8.586
> 28-SEP-2003 09    8.416
> 28-SEP-2003 10    9.327
> 28-SEP-2003 11    8.478
> 28-SEP-2003 12    9.028
> 28-SEP-2003 13    8.879
> 28-SEP-2003 14    9.013
>
>        I need to modify the output format   1) customize the header, 
> get rid of the Z(meters) information
>  2) add some customized words into the header
>  3) list the dat using the following format, ideally tab seperated
>          Day.Hour(local)   Year_Day   Wind_Speed(m/sec)   
> Wind_Direction(deg)
>     9/25/03 0:00               131.23                        
> 4.2                   32
>     9/25/03 1:00                   131.27                    
> 3.8                 30
>                    My questions is
>        1) is ferret powerful enough to generate the output I want?
>        2)  Right now I'm using a Matlab toolbox to work
> on the netcdf file. Any  netcdf tool is able to generate the output or 
> extract pure ascii data
> without the header information?
>
>        Any information will be highly appreciated.
>        Cheers, Ding
>