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Mask to 0 (or a constant) for a selected region

Added by Bidyut Goswami almost 5 years ago

I have a file of dimension Lat x Lon x Time. I want to mask all values to zero except for a region, for all time steps. Or other way around, mask all values to zero only for a particular region, for all time step.  Please suggest. Thanks.


Replies (7)

RE: Mask to 0 (or a constant) for a selected region - Added by Bidyut Goswami almost 5 years ago

I have tried masklonlatbox, maskindexbox, setclonlatbox and maskregion. But I am getting the error "(Abort): Too many different grids!". I am using CDO version 1.9.3.

RE: Mask to 0 (or a constant) for a selected region - Added by Ralf Mueller almost 5 years ago

hi!

Please upload some sample data for further investigation

cheers
ralf

RE: Mask to 0 (or a constant) for a selected region - Added by Bidyut Goswami almost 5 years ago

Please find the attached input file. I am using the command

cdo -masklonlatbox,50,100,0,30 sst_HadOIBl_bc_0.9x1.25_2000climo_c180511.nc test.nc

sst_HadOIBl_bc_0.9x1.25_2000climo_c180511.nc (10.1 MB) sst_HadOIBl_bc_0.9x1.25_2000climo_c180511.nc Input file

RE: Mask to 0 (or a constant) for a selected region - Added by Ralf Mueller almost 5 years ago

hi!

there are variables on a single gridpoint in your input, that's why masking does not work for all of them. for your file, you can select the variables on a horizontally distributed grid with 

-select,'name=ice*,SST*'
or 
-selgrid,1

Basically CDO gets confused by your date-related variables
cdo sinfov sst_HadOIBl_bc_0.9x1.25_2000climo_c180511.nc 
   File format : NetCDF
    -1 : Institut Source   T Steptype Levels Num    Points Num Dtype : Parameter name
     1 : unknown  unknown  v instant       1   1         1   1  I32  : date          
     2 : unknown  unknown  v instant       1   1         1   1  I32  : datesec       
     3 : unknown  unknown  v instant       1   1     55296   2  F32  : ice_cov       
     4 : unknown  unknown  v instant       1   1     55296   2  F32  : ice_cov_prediddle
     5 : unknown  unknown  v instant       1   1     55296   2  F32  : SST_cpl       
     6 : unknown  unknown  v instant       1   1     55296   2  F32  : SST_cpl_prediddle
   Grid coordinates :
     1 : generic                  : points=1
     2 : lonlat                   : points=55296 (288x192)
                              lon : 0 to 358.75 by 1.25 degrees_east  circular
                              lat : -90 to 90 by 0.9424084 degrees_north
   Vertical coordinates :
     1 : surface                  : levels=1
   Time coordinate :  12 steps
     RefTime =  0000-01-01 00:00:00  Units = days  Calendar = 365_day
  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss
  0000-01-16 12:00:00  0000-02-15 00:00:00  0000-03-16 12:00:00  0000-04-16 00:00:00
  0000-05-16 12:00:00  0000-06-16 00:00:00  0000-07-16 12:00:00  0000-08-16 12:00:00
  0000-09-16 00:00:00  0000-10-16 12:00:00  0000-11-16 00:00:00  0000-12-16 12:00:00
the reference date wrong and the variables date and datesec are not CF-conform and get ignored.

hth
ralf

RE: Mask to 0 (or a constant) for a selected region - Added by Bidyut Goswami almost 5 years ago

Hi Ralf,

Thanks for your reply. Did you mean:

cdo -select,name=SST_cpl -masklonlatbox,50,100,0,30 sst_HadOIBl_bc_0.9x1.25_2000climo_c180511.nc test.nc

But I am still getting the same error.

Kindly suggest.

RE: Mask to 0 (or a constant) for a selected region - Added by Ralf Mueller almost 5 years ago

CDO commands are evaluated from right to left. selection needs to be done before the masking:

cdo -masklonlatbox,50,100,0,30  -select,name=SST_cpl sst_HadOIBl_bc_0.9x1.25_2000climo_c180511.nc test.nc

hth
ralf

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