CDO

Hi, I'm using cdo collgrid to merge netCDF files from an LES model, which creates it's output in horizontal tiles. I'm using cdo 2.0.3 on Arch Linux. The data comes from DALES, https://github.com/dalesteam/dales .

I have two problems:
1) in the merged file, the horizontal coordinate variables (xt, xm, yt, ym) are missing.
2) if I don't specify the number of tiles in X, all tiles get merged in a single row

The grid is cartesian, and if I understand the documentation right cdo should handle this without having to specify NX. One possible complication is that the model uses a staggered grid, so different variables use different coordinate variables. xt,yt are cell centers while xm, ym are on cell borders.

Here is an example with 2 x 2 tiles, files attached.

cdo collgrid crossxy.0002.*.nc merged-crossxy.nc
# all tiles are merged horizontally, xt,yt,xm,ym missing

# explicitly specify 2 tiles in X direction
cdo collgrid,2 crossxy.0002.x000y000.001.nc crossxy.0002.x001y000.001.nc  crossxy.0002.x000y001.001.nc  crossxy.0002.x001y001.001.nc merged-crossxy2.nc
# xt,yt,xm,ym missing