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Insert a single Lat and Lon point to NETCDF

Added by Rodrigo Sousa almost 3 years ago

Hello,

I can currently extract a single point from a netcdf with:

cdo -outputtab,date,lon,lat,value -remapnn,"lon=9.0_lat=54.0" infile.nc > output.csv

I was wondering if I can do the opposite.

Insert a single point in netcdf, for example:
lon=9
lat=54
precipitation=25

Is that possible in CDO?


Replies (2)

RE: Insert a single Lat and Lon point to NETCDF - Added by Karin Meier-Fleischer almost 3 years ago

Hi Rodrigo,

the operator setclonlatbox can change the data values of a single cell or a subregion. It is a little bit tricky to change the value for a single point location because you have to set a range where the point is the center of it.

Create test data:

cdo -f nc -topo topo.nc

Show the value at lon=0.0/lat=0.0:

cdo -infon -remapnn,"lon=0.0_lat=0.0" topo.nc

cdo(1) remapnn: Process started
    -1 :       Date     Time   Level Gridsize    Miss :     Minimum        Mean     Maximum : Parameter name
cdo(1) remapnn: Nearest neighbor weights from lonlat (720x360) to lonlat (1x1) grid
     1 : 0000-00-00 00:00:00       0        1       0 :                 -4947.0             : topo   

Change the value at position lon=0.0 / lat=0.0 to 100000:

cdo -setclonlatbox,100000,-0.25,0.25,-0.25,0.25 topo.nc outfile.nc

Let's see the result:

cdo -infon -remapnn,"lon=0.0_lat=0.0" outfile.nc

cdo(1) remapnn: Process started
    -1 :       Date     Time   Level Gridsize    Miss :     Minimum        Mean     Maximum : Parameter name
cdo(1) remapnn: Nearest neighbor weights from lonlat (720x360) to lonlat (1x1) grid
     1 : 0000-00-00 00:00:00       0        1       0 :              1.0000e+05             : topo          
cdo(1) remapnn: Processed 259200 values from 1 variable over 1 timestep.

-Karin

RE: Insert a single Lat and Lon point to NETCDF - Added by Rodrigo Sousa almost 3 years ago

Hi Karin.

It was a question that I thought and wanted to know if I had how to do it in CDO.

I'll try this procedure.

Thanks.

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