float problem

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: float problem
• From: Foccroulle@xxxxxxxxxxxxxx (Jean-Francois Foccroulle)
• Date: Tue, 26 Apr 1994 17:09:38 GMT

Hello,
We use netCDF and sometimes create and read netCDF files with different computer
 s.
Unfortunately I have found a problem when reading a (very) small float from
a netCDF file on a DEC ALPHA (OSF/1).
I can read this float on a convex and on a DECstation 5000/125 (ultrix). The val
 ue is
approximatively 0..

When I use ncdump
   -on a convex
        netcdf wkxy3 {
           dimensions:
                lon = 1 ;
           variables:
                float wkxy3(lon) ;
           data:
           wkxy3 = 0  ;
        }
   -on a DECstation 5000
        netcdf wkxy3 {
           dimensions:
                lon = 1 ;
           variables:
                float wkxy3(lon) ;
           data:
           wkxy3 = 1.401298e-45  ;
        }
   -on a DEC ALPHA,
        a floating exception occurs and a core dump is created.

I guess the origin of the problem is the value itself (less than FLT_MIN)
But the DECstation 5000 behaviour is better as well as the Convex ...
Do you have any suggestion to read properly small float values on a DEC ALPHA ?
I give you below the netCDF file, encoded with uuencode.
Thanks for your help,


Jean-Francois Foccroulle, jf@xxxxxxxxxxxxxx
Institut d'Astronomie et de Geophysique
1348 Louvain-la-Neuve
Belgium


begin 644 wkxy3.nc
M0T1&`0`````````*`````0````-L;VX``````0``````````````"P````$`
K```%=VMX>3,````````!````````````````````!0````0```!4`````0$`
`
end