CDO

Unfortunately, it is not possible to change names with CDO if they contain a comma.
It is also not possible with the NCO tool ncrename.

Cheers,
Uwe

Hi Shoaib,

usually there is a solution with NCL when CDO can't do something, so here too.

The following NCL script changes the variable name in the output file:

;-- open file
f = addfile("pop1_2000.nc", "r")

;-- retrieve the variable names
varnames = getfilevarnames(f)

print("---------------------------------------------------------")
print("Variable names: "+varnames)
print("---------------------------------------------------------")

;-- in this case the desired variable is varnames(3)
printVarSummary(f->$varnames(3)$)
print("---------------------------------------------------------")

;-- if already existing, delete new output file
system("rm -rf pop1_2000_new.nc")

;-- open output file
fout = addfile("pop1_2000_new.nc", "c")

;-- write data to output file; new variable name 'population'
fout->population = f->$varnames(3)$

printVarSummary(fout->population)
print("---------------------------------------------------------")

Run the script in a terminal:

ncl chname.ncl

Output of 'ncdump -h pop1_2000_new.nc':

netcdf pop1_2000_new {
dimensions:
    time = 1 ;
    latitude = 180 ;
    longitude = 360 ;
variables:
    float population(time, latitude, longitude) ;
        population:long_name = "Population Density, v4.11 (2000, 2005, 2010, 2015, 2020): 1 degree" ;
        population:units = "Persons per square kilometer" ;
        population:_FillValue = -3.4e+38f ;
        population:missing_value = -3.4e+38f ;
        population:min = 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 4., 0., 0., 0., -9999., -9999., 0., 0., 0., 0. ;
        population:max = 11538.9345703125, 11883.712890625, 12329.0302734375, 12901.76953125, 13639.572265625, 207., 767642., 3., 12391.3994140625, 12322.5126953125, 32767., 6., 2015., 6., 6., 6., 2011., 2015., 4., 2016. ;
    double time(time) ;
        time:standard_name = "time" ;
        time:units = "day as %Y%m%d.%f" ;
        time:calendar = "proleptic_gregorian" ;
        time:axis = "T" ;
    double latitude(latitude) ;
        latitude:standard_name = "latitude" ;
        latitude:long_name = "latitude" ;
        latitude:units = "degrees_north" ;
        latitude:axis = "Y" ;
    double longitude(longitude) ;
        longitude:standard_name = "longitude" ;
        longitude:long_name = "longitude" ;
        longitude:units = "degrees_east" ;
        longitude:axis = "X" ;
}

-Karin

Thank you karin