Re: Ascii file: switching X Y data

[Jaison Kurian <jaison@xxxxxxxxxxxxxxxxxx>]

Hi Kek,
 The problems associated with the format of your ascii data are

     1. Due to the prescence of "Time/Depth" & "08:00:00" fields in the 
             first column we need to use the qualifiers 
             FORMAT=DELIMITED/DELIMITER=" " along with the file command.
             In this case  /COLUMNS won't be effective to read along a row
             instead of the default columnwise reading.
     2. It is not possible to skip first column and read the remaining
             data block along rows using /COLUMNS qualifier to a single 
             variable. 

 Here is one way to tackle this (ofcourse not a 'neat' one). I took a case
 with 8 depth points and 5 time points exactly like the format you specified.

-----datafile.dat------------------------------------------
Time/Depth  2.0   4.0   9.0   15     25    40    75    100
08:00:00   33.3   32.2  31.4  31.0   30.3  30.0  29.6  29.4
09:00:00   35.3   31.2  30.4  29.5   29.0  28.4  28.2  27.4
10:00:00   39.3   37.2  37.4  36.3   35.2  34.4  33.2  32.4
15:00:00   32.3   35.2  33.4  32.3   31.2  30.4  29.4  29.0
17:00:00   31.3   31.2  31.4  31.0   30.5  30.0  29.6  29.0
----end of datafile.dat------------------------------------

!----example.jnl--------------    
!
! Read only the depth values from 1st row and then convert this 
!   values to a 1D array. Then use this values to define a depth
!   axis
     
   define symbol com = FORMAT=DELIMITED/DELIMITER=" " ! to make command lines 
                                                      !    shorter
   define axis/x=1:1:1 xax
   define grid/x=xax grd
   file/grid=grd/($com)/var="-,d1,d2,d3,d4,d5,d6,d7,d8" datafile.dat
   let dep = ZSEQUENCE({`d1`,`d2`,`d3`,`d4`,`d5`,`d6`,`d7`,`d8`})
   define axis/z/units="meters"/DEPTH/from_data zdep=dep        

! Read time from second row onwards and define a time axis.
!   it is assumed that the data is for 01-JAN-2003.

   file/skip=1/($com)/type=time/var=tim datafile.dat
   define axis/t/units=hours/T0="01-JAN-2003"/from_data thr=tim

! Read the data values of the variable('-' is to skip the time data)
! and write it to a dummy file. Then read it back onto a grid defined by
! those depth and time axes from the dummy file

  file/skip=1/($com)/var="-,v1,v2,v3,v4,v5,v6,v7,v8"
  sp rm -f dummy.dat ! initial clean-up
  list/nohead/quiet/file=dummy.dat/format=(8(f5.2,2x))/append v1,v2,v3,v4,v5,v6,v7,v8
  define grid/z=zdep/t=thr vgrd
  file/grid=vgrd/columns=8/var=myvar dummy.dat
  set var/title="My Variable"/units="my units" myvar

! Now the data is on proper grid; do the plotting/calculation steps.
! I would strongly recommend you to save this data to a netCDF file using
! "SAVE" commad for later use.

  plot/l=1 myvar
  ! save/file=myvar.nc/append myvar

! Remove the dummy file

  sp rm -f dummy.dat

!--------------end of example.jnl--------------


 Hope this Helps 

 With Regards 

 Jaison





On Sat, 21 Aug 2004 hengkek@nus.edu.sg wrote:

> Greetings all
> 
> I have the following ascii file.  
> 
> ---------- start file -----------
> Time/Depth  2.0   4.0   9.0 ...
> 08:00:00   33.3   32.2  31.4 ...
> 09:00:00   35.3   31.2  30.4 ...
> 10:00:00   39.3   37.2  37.4 ...
> 15:00:00   32.3   35.2  33.4 ...
> 17:00:00   31.3   31.2  31.4 ...
> ...
> ---------- end file -----------
> File Description:
> 1st col: time  values
> 1st row: depth values
> Other vals: measurements at the given time and depth
> 
> I'm able to plot the timeseries at each depth.  My difficulty now is in
> plotting the measurements against depth without transposing the ascii
> file.  I.e. Y axis to be "depth" and X axis to be "measurement".
> 
> I did the following for the timeseries.  How do I proceed to plot
> against depth?  I know I must now not skip the 1st row to get the depth
> values.  Thanks in advance for any pointers or leads.
> -----
> columns/skip=1/type=time,numeric,numeric,numeric,numeric,numeric,\
> 	numeric,numeric,numeric,numeric,numeric,numeric,numeric, \
> 	numeric,numeric,numeric,numeric,numeric,numeric,numeric, \
> 	numeric,numeric,numeric,numeric,numeric,numeric,numeric, \
> 	numeric,numeric,numeric,numeric,numeric,numeric,numeric, \
> 	numeric,numeric,numeric,numeric  EW_010804.txt
> plot/vs/line v1,v2,v3,v4,v5,v6,v7,v8
> -----
> 
> Regards
> -Kek
> Tropical Marine Science Institute
> Singapore
> 

-- 
___________________________________________________

    Jaison Kurian                           
    Centre for Atmospheric and Oceanic Sciences
    Indian Institute of Science
    B A N G A L O R E   560 012
    Ph: +91-80-3942505
        +91-80-3600450
    Fax:+91-80-3600865
___________________________________________________