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Warning (cdfInqContents): Coordinates variable XTIME can't be assigned!

Added by Dragan Petrovic about 2 years ago

I have a high number of daily WRF outputs, each one consisting of 24 time steps for every single hour of the day. Now I would like to combine these single output files to one resulting file that comprises the entire time period by using "cdo mergetime". I have done this before with some other output files in another context and it worked well.

When I apply this command for example:

cdo mergetime wrf_file1.nc wrf_file2.nc output_file.nc

I get the following message many times: "Warning (cdfInqContents): Coordinates variable XTIME can't be assigned!"

Since it is only a warning and not an error, the process continues. But it takes way too much time and the resulting output file is way too big. For example, when the two input files are about 6 GB, the resulting output file is above 40 GB, which does not make sense at all.

Anybody with an idea, how to solve this?


Replies (3)

RE: Warning (cdfInqContents): Coordinates variable XTIME can't be assigned! - Added by Ralf Mueller about 2 years ago

hi Dragan!

in case your files are already sorted temporally you dont need mergetime. Instead you can use cat

WRF has a strange dimension/coordinates names. maybe a bit of preprocessing is needed, too. but for that I need to have at least 2 of your files. maybe you can select a single variable (or timestep) and upload it here.

cheers
ralf

RE: Warning (cdfInqContents): Coordinates variable XTIME can't be assigned! - Added by Dragan Petrovic about 2 years ago

Hi Ralf,

thanks for your answer. The command "cat" works indeed, but the output file is too large. I combined two files, each of about 6 GB size, and the output file has 48 GB. This is too large to work with, since there are more files I would like to combine.

In the meanwhile I found a sort of solution. When I first extract the variables I need by "selname" than all commands work afterwards and the computation time and the output file size are always acceptable. So it seems like you were right, some kind of post processing was needed first.

RE: Warning (cdfInqContents): Coordinates variable XTIME can't be assigned! - Added by Ralf Mueller about 2 years ago

happy to help - selection of what you need as first step is a very useful practice IMO.

have a nice weekend
ralf

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