Hello,
I'm trying to write unsigned data to attributes, but I can't quite get it
working. I've seen the mailing list threads on reading from unsigned
attributes, but I haven't seen much discussion about writing.
Suppose I have an unsigned byte variable, and I want to set its `valid_range`
attribute. I tried using `Array.setUnsigned`, but the values are still written
as signed. In this case the valid range is 0..255, which comes out as 0..-1.
This causes ToolsUI to read the variable as being empty.
I would just use shorts instead of bytes, but this approach does not seem to be
reliable for all attributes: it fails for the `_FillValue` attribute which the
nc4 IOSP says must be the same type as the variable.
I asked a question on StackOverflow; it has some simplified code in it:
http://stackoverflow.com/questions/17139391/netcdf-java-how-to-write-unsigned-attribute
Versions:
- NetCDF-Java 4.3.16
- libnetcdf 4.2.1
- ToolsUI 4.3
Let me know if you need more information.
Cheers,
Alex
--
Alex Fraser
Software Engineer
VPAC Ltd.
