[ferret_users] binary file output is garbled Re: question about binary file writing in ferret: doubling of size with repeat

[Lev Tarasov <lev@xxxxxx>]

Should have checked the output first:

Ferret Binary output is garbled when read in fortran:

file was output in ferret as

 set region /J=10801
 LIST /FORMAT=UNF/FILE=GEBCO_2D_1min.bincollatrec ELEVATION

 can region
 repeat /J=10800:1:-1 LIST /FORMAT=UNF/APP/FILE=GEBCO_2D_1min.bincollatrec ELEVATION

and the data set should have 21601 entries from just the first list command:

    1> ./GEBCO_global_2D_1min.nc  (default)
 name     title                             I         J         K         L         M         N
 ELEVATION
          Elevation relative to sea level  1:21601   1:10801   ... 
...       ...       ...


in my fortran code I have:

      real*4 rh1(nlond)
..
      open(unit=iu,file=fname,FORM='UNFORMATTED',status='old')
           read(iu) rh1(1:2)
            print *, rh1(1:2)

-5.515991      1.1210388E-44

but this does not match the source data:

yes? list ELEVATION[i=1:2,j=10801]
 180E      / 1: -4227.
 179.983W  / 2: -4227.

And if I try to read the first first 5 values of the binary data,
I get an runtime error:
Fortran runtime error: Short record on unformatted read

What gives?

Cheers,

Lev Tarasov -   Dept of Physics and Physical Oceanography,
		Memorial University of Newfoundland.
                email: lev@xxxxxx
                http://www.physics.mun.ca/~lev/
		Tel (709)-864-2675
		Fax (709)-864-8739

On Tue, 19 Jan 2016, Lev Tarasov wrote:

> Hi all;
> 	to facilitate reuse of some old code, I needed to convert
> a netcdf DEM to binary, with sequential records for each latitude (and 
> colatitude ordering):
> ie:
> set region /J=10801
> LIST /FORMAT=UNF/FILE=GEBCO_2D_1min.bincollatrec ELEVATION
> can region
> repeat /J=10800:1:-1 LIST /FORMAT=UNF/APP/FILE=GEBCO_2D_1min.bincollatrec 
> ELEVATION
>
> this gave
> -rw-r----- 1 3732998416 Jan 19 10:50 GEBCO_2D_1min.bincollatrec
>
> This nearly doubled the size of the file compared to simply
> LIST /FORMAT=UNF/FILE=GEBCO_2D_1min.bin ELEVATION
>
> -rw-r----- 1 1866585616 Jan 19 09:04 GEBCO_2D_1min.bin
>
> Why the doubling?
>
> Cheers,
>
> Lev
>
> Lev Tarasov -   Dept of Physics and Physical Oceanography,
> 		Memorial University of Newfoundland.
>                email: lev@xxxxxx
>                http://www.physics.mun.ca/~lev/
> 		Tel (709)-864-2675
> 		Fax (709)-864-8739