20040720: failure in test of ncgen on NEC SX6

Alistair,

> To: address@hidden
> From: "Sellar, Alistair" <address@hidden>
> Subject: failure in test of ncgen
> Organization: UCAR/Unidata
> Keywords: 200407201523.i6KFNJaW001468

The above message contained the following:

> I'm installing netcdf 3.5.1 on an NEC SX6 and I'd be grateful for any
> advice on whether I should be concerned about the following error.  The
> make step completes OK, but there seems to be small precision errors
> when testing ncgen.  Details included as requested at
> http://my.unidata.ucar.edu/content/software/netcdf/INSTALL.html#ReportingProblems

The ncgen(1) "make test" errors:

> Making `test' in directory /data/cr/ocean/frtq/netcdf-3.5.1/src/ncgen
> 
>       cc -o ncgen -O -size_t64  main.o load.o ncgentab.o escapes.o  getfill.o 
> init.o genlib.o ../libsrc/libnetcdf.a  
>       ./ncgen -b -o c0.nc c0.cdl
>       ../ncdump/ncdump -n c1 c0.nc > c1.cdl
> *** ncgen -b test successful ***
>       ./ncgen -c -o ctest0.nc c0.cdl > ctest.c && \
>       cc -o ctest -O -size_t64  -I../libsrc -I.  -DNDEBUG ctest.c 
> ../libsrc/libnetcdf.a  && \
>       ./ctest && \
>       ../ncdump/ncdump -n c1 ctest0.nc > ctest1.cdl
...
> 21c21
> <             i:d = -1.e+308, 0., 1.e+308 ;
> ---
> >             i:d = -9.99999999999999e+307, 0., 9.99999999999999e+307 ;
> 101c101
> <             :Gd = -1.e+308, 0., 1.e+308 ;
> ---
> >             :Gd = -9.99999999999999e+307, 0., 9.99999999999999e+307 ;
> 128c128
> <  dr = -1e+308, 1e+308 ;
> ---
> >  dr = -9.99999999999999e+307, 9.99999999999999e+307 ;
> 140c140
> <  d1 = -1e+308 ;
> ---
> >  d1 = -9.99999999999999e+307 ;
> 152c152
> <  d2 = -1e+308, 1e+308 ;
> ---
> >  d2 = -9.99999999999999e+307, 9.99999999999999e+307 ;
> 164c164
> <  d3 = -1e+308, 0, 1e+308 ;
> ---
> >  d3 = -9.99999999999999e+307, 0, 9.99999999999999e+307 ;
> *** ncgen -c test failed ***
> *** Error code 1 (bu21)
> make: fatal error.
> *** Error code 1 (bu21)
> make: fatal error.
> *** Error code 1 (bu21)
> make: fatal error.

are actually roundoff errors caused by the hardware of the NEC SX6.  You
should be able to safely ignore them.

I suggest that you install the netCDF package and test it with some
of your own programs.  I expect that it will work correctly.

Regards,
Steve Emmerson

> NOTE: All email exchanges with Unidata User Support are recorded in the
> Unidata inquiry tracking system and then made publically available
> through the web.  If you do not want to have your interactions made
> available in this way, you must let us know in each email you send to us.