dump netcdf variable within a range

Question

I am using the following command to dump the content of the variable 'tas' within a netcdf file tas_EUR-44_historical.nc

ncdump -v tas tas_EUR-44_historical.nc

tas is a variable of three dimensions consisting of time, latitude and longitude tas(time, rlat, rlon)

Now I need to dump the first value of time ,0, for rlat ranging from 0 to 5 and rlon ranging from 0 to 5.

Does anyone know how this can be done?

Thanks!

Charlie Zender · Accepted Answer · 2016-11-20 18:19:08Z

2

You can use ncks

ncks -d time,0 -d rlat,0,5 -d rlon,0,5 in.nc out.nc

answered Nov 20, 2016 at 18:19

Charlie Zender

6,45217 silver badges24 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

David Halley Over a year ago

Dear Charlie, I am aware of this method. What I explicit want is to use ncdump and then visualize values in the requested region without creating an out.nc file.

Charlie Zender Over a year ago

I'm not sure what you mean by visualize. Unlike ncdump, ncks will print the hyperslab of values to screen in CDL format (without generating a .nc file) if you give it the --cdl switch: ncks --cdl -d time,0 -d rlat,0,5 -d rlon,0,5 in.nc

Bart · Accepted Answer · 2016-11-20 18:18:52Z

Strongly depends on what kind of tools you want to use. This is a very trivial task with most programming languages ("Python/R/..."), if you want a command line tool you might want to look at NCO and especially its ncks (NetCDF Kitchen Sink) command.

For example, if I have a NetCDF file (output ncdump -h)

netcdf u.xz {
dimensions:
    xh = 256 ;
    y = 1 ;
    z = 160 ;
    time = UNLIMITED ; // (481 currently)
variables:
    float time(time) ;
        string time:units = "Seconds since start of experiment" ;
    float xh(xh) ;
    float y(y) ;
    float z(z) ;
    float u(time, z, xh, y) ;
}

I can extract for example the first time record using:

ncks -d time,0,0 u.xz.nc test.nc

Or, something closer to your question, select the first time record and slice the spatial dimensions:

ncks -d time,0,0 -d xh,0,5 -d z,0,5 u.xz.nc test.nc

Each time the manipulated NetCDF file is written to a new file. You can leave out the last argument test.nc to dump the output to screen, or simply dump the output of test.nc with ncdump.

Collectives™ on Stack Overflow

dump netcdf variable within a range

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related