[ferret_users] BUG REPORT: Appending packed NetCDF data

[Russ Fiedler <russell.fiedler@xxxxxxxx>]

Hi,

There appears to be a serious bug when trying to append packed data to a
file.

I have temperature, say, which is packed to a 2 byte integer with the
attributes scale_factor and add_offset.


        short temp(Time, st_ocean, yt_ocean, xt_ocean) ;
                temp:missing_value = -32768s ;
                temp:_FillValue = -32768s ;
                temp:long_name = "Potential temperature" ;
                temp:units = "degrees C" ;
                temp:scale_factor = 0.001678518f ;
                temp:add_offset = 45.f ;
                temp:history = "From ocean_temp_1994_01" ;
...
 temp =
  -9714,
  -9750 ;

These come out to be 

01-JAN-1994 12 / 1:  28.69
02-JAN-1994 12 / 2:  28.63



If I attempt to save this all at once then no problem...

set var/outtype=int2 temp
set att/output temp.scale_factor
set att/output temp.add_offset
save/clob/file=dummy1.nc/l=1:2 temp

yes? sp ncdump  dummy1.nc | tail  -n 4
 
 temp =
  -9714,
  -9750 ;
}


Now if I try to save the first value and then append the second

 save/clob/file=dummy2.nc/l=1 temp
 save/app/file=dummy2.nc/l=2 temp

yes? sp ncdump  dummy2.nc | tail -n 4
  -0.100000003352761, 0 ;

 temp =
  -9714,
  28 ;                    <<<<<<<<<<<<<<<<<<<<<<<<<<<<<< 
}

Ferret just appends the integer part of the the temperature rather than
doing any scaling.


russ-hf% ferret -nojnl
        NOAA/PMEL TMAP
        FERRET v6.82  
        Linux 2.6.32-279.1.1.el6.x86_64 64-bit - 08/03/12


Russ

Attachment: dummy.nc
Description: Cdf file

Attachment: dummy1.nc
Description: Cdf file

Attachment: dummy2.nc
Description: Cdf file