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Hi Huaiyu, > This bug seems to be related to an earlier discussion I had with Russ > and Ed about ticket #RUF-772159. I enabled logging in ncdump > (4.1-beta2) and get the following error message: > =========================================== > ... > read_var: obj_name position > read_var: about to iterate over scales for dim 0 > read_var: about to iterate over scales for dim 1 > ERROR: file nc4file.c, line 1275. > HDF error > ERROR: file nc4file.c, line 1449. > HDF error > ERROR: file nc4file.c, line 1701. > HDF error > =========================================== > Here variable "position" has 4 dimensions, "snapshot" (unlimited), > "slice", "particle" and "axis". My code also defines variables > "snapshot", "slice", "particle" and "axis" with the corresponding > dimension. It turns out that the netcdf file becomes unreadable if > these dimension variables are defined after "position". There are > several strange things about this bug: > (1) Netcdf does not report any error when the file was created. > Actually data can be written while the program is running. > (2) Although the file cannot be read by a ncdump which reports HDF > error, it can be read by HDF utility program such as hdfview. > (3) The error goes away if the "slice" dimension is removed. In > addition, I cannot reproduce the error in a simple example code. > > I know it is very difficult to catch this bug. Again I can send you > the netcdf file if you need it. Yes, please make the netCDF file available to us. Perhaps with h5dump or hdfview, we can figure out what the problem is. Thanks. --Russ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: ZCH-634698 Department: Support netCDF Priority: Normal Status: Closed