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bottomvalue returning the top

Added by Brendan DeTracey about 3 years ago

When I run bottomvalue on the attached file, it returns the top layer. I don't understand why it does not use value of lev to determine the vertical.

$ cdo -v bottomvalue thetao_Omon_MIROC6_historical_r13i1p1f1_gn_201001.nc test.nc
 OpenMP:  num_procs=24  max_threads=1
cdo    bottomvalue: Isoval: 0
cdo    bottomvalue: Processed 5898612 values from 7 variables over 1 timestep [0.20s 97MB].

thetao_Omon_MIROC6_historical_r13i1p1f1_gn_201001.nc (38.8 MB) thetao_Omon_MIROC6_historical_r13i1p1f1_gn_201001.nc

Replies (6)

RE: bottomvalue returning the top - Added by Brendan DeTracey about 3 years ago

And topvalue returns the bottom. :(

RE: bottomvalue returning the top - Added by Uwe Schulzweida about 3 years ago

Hi Brendan,

The operators bottomvalue and topvalue uses the NetCDF CF compliant attribute positive to determine where top and bottom are. If this attribute is missing, low values are bottom and high values are top.

Cheers,
Uwe

RE: bottomvalue returning the top - Added by Karin Meier-Fleischer about 3 years ago

Hi, do I miss something? I can't find the operators bottomvalue and topvalue in the documentation or with --operators. :(

RE: bottomvalue returning the top - Added by Uwe Schulzweida about 3 years ago

Hi Karin, these operators are new and will be documented in the next release.

RE: bottomvalue returning the top - Added by Brendan DeTracey about 3 years ago

This file is pathological. I ended up treating it as a special case and used topvalue to get the bottomvalue. I tried deleting all vertical variables except lev. I also tried invertlev. bottomvalue continued to return the top layer.

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