Project

General

Profile

average/sum over any chosen dimension

Added by Erik Noble almost 12 years ago

Hi. Maybe I am missing it in the CDO refcard or the documentation, but is there a command for averaging a variable/ file over one of its dimensions, not just time?

For instance, if I have rain(time,lat,lon), and I want rain(time,lon) averaged over lat, is there a command for this?
Sincerely,
Erik


Replies (5)

RE: average/sum over any chosen dimension - Added by Jaison-Thomas Ambadan almost 12 years ago

Hi Erik,

Yes off-course CDO has all the operators that you need!

See CDO documentation, Section 2.8.7 MERSTAT - Meridional statistical values

For mean, the operators are "mermean" or "meravg"

https://code.zmaw.de/embedded/cdo/1.5.4/cdo.html#x1-2880002.8.7

For Zonal average: see section 2.8.6 ZONSTAT - Zonal statistical values

https://code.zmaw.de/embedded/cdo/1.5.4/cdo.html#x1-2880002.8.6

Also, just for your info: CDO mean and average calculations are slightly different, depends on the input data (this applies to all operators involving "mean" or "avg")

For more info see: https://code.zmaw.de/embedded/cdo/1.5.4/cdo.html#x1-290001.7.1

Hope this helps!

Cheers,
J.

RE: average/sum over any chosen dimension - Added by Ralf Mueller almost 12 years ago

And there is VERTSTAT for vertical operations.

RE: average/sum over any chosen dimension - Added by Erik Noble almost 12 years ago

Thank you.

One last question in the same area?

Lets say I have a file of 3-hourly rain accumulation (time, lat, lon) and I want create a 'sum' over time to create daily fields, in one file, which command can help me do this?
TIMSELSTAT? If so, how?

I have been using the following steps:
cdo splitday $FILE day_
and then
FILES=`ls day_*.nc
for i in $FILES
do
cdo timesum $i temp_$i
done

and then
cdo mergetime temp_*.nc $FILE_daily.nc

Is there a more efficient way to do this with one command?
-Erik

RE: average/sum over any chosen dimension - Added by Uwe Schulzweida almost 12 years ago

cdo daysum $FILE $FILE_daily.nc

RE: average/sum over any chosen dimension - Added by Sopan kurkute about 9 years ago

Very useful information. Thank you very much

    (1-5/5)