In 2.5.1 of CF 1.4:
"The missing_value attribute is considered deprecated by the NUG and we do not recommend its use. However for backwards compatibility with COARDS this standard continues to recognize the use of the missing_value attribute to indicate undefined or missing data."
Although there was a short time when a version of the User Guide deprecated the missing_value attribute, this is no longer the case. We decided that the deprecation was a mistake, and that deprecation hasnt been in the NUG for a long time now. What it now says is
http://www.unidata.ucar.edu/software/netcdf/docs/netcdf.html
(Appendix B) :
missing_value
This attribute is not treated in any special way by the library or conforming generic applications, but is often useful documentation and may be used by specific applications. The missing_value attribute can be a scalar or vector containing values indicating missing data. These values should all be outside the valid range so that generic applications will treat them as missing.
I get enough questions about this that id like to propose removing this paragraph from the CF standard. If no one objects, ill open a ticket.
Received on Thu Mar 18 2010 - 21:49:54 GMT
