[gradsusr] Convert text data to Binary using GrADS script

[Bradley NAVARRO]

Hi all,

I know GrADS has the ability to convert regular numerical text to binary, which is ideal because while I can do it with Fortran, I’d prefer to be able to do everything in GrADS in one script. Before I get to the issue, here are the ‘q config’ data:

Built Fri Nov  9 13:38:49 MST 2012 for i686-pc-linux-gnu

This version of GrADS has been configured with the following options:
  o Built on a LITTLE ENDIAN machine
  o Athena Widget GUI DISABLED
  o Command line editing ENABLED 
      http://tiswww.case.edu/php/chet/readline/rltop.html 
  o printim command for image output ENABLED 
      http://www.zlib.net 
      http://www.libpng.org/pub/png/libpng.html 
      http://www.libgd.org/Main_Page 
  o GRIB2 interface ENABLED 
      http://www.ijg.org 
      http://www.ece.uvic.ca/~mdadams/jasper 
      http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2 
      g2clib-1.4.0  
  o NetCDF interface ENABLED 
      http://www.unidata.ucar.edu/software/netcdf  
      netcdf 4.1.2 of Oct  6 2011 13:44:26 $  
  o OPeNDAP gridded data interface ENABLED
  o OPeNDAP station data interface ENABLED
      http://iges.org/grads/gadoc/supplibs.html 
      libgadap 2.0  
  o HDF4 and HDF5 interfaces ENABLED 
      http://hdfgroup.org 
      HDF 4.2r3 
      HDF5 1.8.7 
  o GeoTIFF and KML/TIFF output ENABLED
      http://www.libtiff.org 
      http://geotiff.osgeo.org 
  o KML contour output ENABLED
  o Shapefile interface ENABLED
      http://shapelib.maptools.org 


Ok, so now on to the issue. Basically, I have some output written to a file called result.txt where each row is a latitude and each column is a longitude. Thus the file is 181 latitude x 360 longitude. It starts at -90 and ends at 90, 0 to 359 degrees longitude.  I have 21 time steps so a total of 3801 lines (181 * 21 = 3801). I use a simple script using fwrite to take each line and convert to binary. Below is the basic script (I have left out the dummy.ctl file for clarity):

file='result.txt'
'set gxout fwrite'
'set fwrite result.bin'
res=read(file)
rc=sublin(res,1)
while(rc=0)
 line=sublin(res,2)
 'd 'line
 res=read(file)
 rc=sublin(res,1)
endwhile
'disable fwrite'


When I run the above script, it seems to run fine. I get a file called result.bin with 15204 bytes. I then run the control file to try to plot the newly converted binary data:

dset ^result.bin
undef 9.999E+20
title analog damage areas
ydef 181 linear -90 1
xdef 360 linear 0 1
tdef 21 linear 06Z23SEP2020 6hr
zdef 1 linear 1 1
vars 1
damage  0,0   0,0,0 **  areas where damage detected
ENDVARS

I then get the following error:

ga-> set t 1
Time values set: 2020:9:23:6 2020:9:23:6 
ga-> d damage
Low Level I/O Error:  Read error on data file 
  Data file name = result.bin 
  Error reading 1440 bytes at location 14400 
Data Request Error:  Error for variable 'damage'
  Error ocurred at column 1
DISPLAY error:  Invalid expression 
  Expression = damage

I can confirm that the original result.txt file contains 181 x 360 data points for 21 time steps. But the byte size of the binary file seems to be smaller than I would expect, maybe? I’ve tried much from the archives to try to figure this issue out but perhaps my understanding is lacking and I am now out of ideas. And just for reference, I can run result.txt through a Fortran script to convert to binary and the resulting file plots perfectly fine with the control file above. But like I said, it seems like I should be able to do the conversion in GrADS. Any help on this issue would be greatly appreciated.

Thanks,
Brad

 
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