It seems to me that possibly I am looking at a dialect of netCDF,
literally "Convention" = "CF-1.0":
i.e. http://www.cgd.ucar.edu/cms/eaton/netcdf/CF-20010629.htm
Which has a ton of theoretical, this field, that field, this, that,
and the other attribute name, purpose, etc.
However, what I am interested in finding are apparent deviations from
the core netCDF file structure. I am 99% positive that the file format
as described in the VERSION \x01 format specification is not being
adhered to where gatt_list (more generally, att_list). The first
attribute has a type associated with it that I can find, but ones
thereafter seem to ignore this field. But even that is inconsistent.
Even taking the separation between header (meta description) and data
(fixed, followed by record, data), it is possible i am misinterpreting
the relationship between attributes, dimensions, etc, but not if I
read straight from the BNF and work it out like according to its
logical AST outworking.
Is there no one on this list who has any knowledge of this, or where
else I might be likely to find these details?
Thank you...
---------- Forwarded message ----------
From: Michael Powell <mwpowellhtx@xxxxxxxxx>
Date: Sun, May 10, 2015 at 11:26 PM
Subject: Help with reading cdf attr_list attr
To: netcdfgroup@xxxxxxxxxxxxxxxx
Hello,
I could be reading the file format wrong, but I am reading the parts
as specified in the BNF. Possibly (POSSIBLY), I need to wait for
fixed-length data until after reading the header, but even with that,
I fail to account for the attr::nelems or the corresponding nc_type,
before what looks like the next attr finds its way into the header, at
least in a couple of the examples I am trying to read.
http://www.unidata.ucar.edu/software/netcdf/docs_rc/file_format_specifications.html
http://www.unidata.ucar.edu/software/netcdf/examples/files.html
att_list = ABSENT | NC_ATTRIBUTE nelems [attr ...]
attr = name nc_type nelems [values ...]
I am new (refreshing) with CDF, so I am likely not interpreting
something quite right, or it's an undocumented gotcha.
Would someone kindly look into this and let me know? I'm sure there's
some nuance about the format versus the BNF that I am failing to
comprehend somehow.
Thank you...
Best regards,
Michael
