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

[Lev Tarasov <lev@xxxxxx>]

Hi Ansley;
	I had already tried reading the data as real*8,
	and just reading the first field value gave a  garbled result:
        1.857317845909682E-313 (supposed to be -4227.)

and
INTEGER, PARMETER :: nlond=360*60+1
real*8 rh1(nlond)
read(iu) rh1(1:2)
gives:
Fortran runtime error: Short record on unformatted read

version
 	FERRET v6.93
 	Linux 2.6.9-89.ELsmp 64-bit - 11/18/14


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, Ansley C. Manke wrote:

> Hi Lev,
> Double -precision Ferret will write double-precision output.  So that would 
> be the first thing to test; perhaps write some small test files and read the 
> data using a short Fortran test program, reading into variables declared as 
> real*8.
>
> There is not an option to write single-precision data with double-precision 
> versions of Ferret; binary and stream file IO is in Ferret but not actively 
> supported.
>
> Ansley
>
>
> On 1/19/2016 7:39 AM, Lev Tarasov wrote:
> > 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