This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
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.