How to edit a specific variable inside a Netcdf file?

Hi guys; I have a netcdf file (.nc) and I would like to do some editing on this file by using matlab. I first use the following command to read the file:

ncid=netcdf.open('GROM-hind-crv-bot-10-05-19-00-thru-10-05-21-00.nc','NC_WRITE');

Then, by using the netcdf.inq(ncid) command:

[numdims numvars numatts unlimdimID] = netcdf.inq(ncid)

I get:

numdims =

     3

numvars =

     7

numatts =

     7

unlimdimID =

     2

As shown, there are 7 variables in the section of variables. I want to delete one of the variables. In other words, I want to change number of variables from 7 to 6 by deleting one of them. Could you please help me about that. I am pretty new to netcdf package in Matlab and I do appreciate if everyone could help me about that. Thanks Reza

Answer 1

[Ashish Uthama]

NetCDF does not let you delete a variable from a file.

Your best bet is to create a new file from the existing one, copying over all BUT the one you want to delete.

[Ashish Uthama]

The 2011a feature |ncwriteschema|: http://www.mathworks.com/help/techdoc/ref/ncwriteschema.html will be useful if you choose to go this route.

[Kelly Kearney]

Though if you're going to go the new file method (which I agree is the easiest way to delete a variable, though a bit of a pain if you're working with large files), it's probably easier to use NCO (<http://nco.sourceforge.net/>) than Matlab:

ncks -x -v varToBeDeleted oldfile.nc newfile.nc