Changes between Initial Version and Version 1 of HowTo_cdo_netcdf

Timestamp:

2014-11-21T11:01:09+01:00 (10 years ago)

Author:

zpoussi

Comment:

--

HowTo_cdo_netcdf

@@ +1 @@
+== ncap2 ==
+
+the most powerful and quickly evolving tool from the nco set of functions
+
+See the file of exemples : {{:reunions_orchidee:ncap2.pdf| ncap2 file}} or search what you are looking on this growing list of answers [[http://sourceforge.net/search/index.php?words=&sort=posted_date&sortdir=desc&offset=0&group_id=3331&type_of_search=forums|forum nco]]
+
+A simple exemple showing different capacities (creation of a variable, use of a mask, call to an attribute, count the total and the size of the field (we can restrict this operation to a dimension as shown on the second line)
+
+<code>
+ ncap2 -O -s 'missing_flag[$y,$x]=0;where(t2m_daily!=t2m_daily@missing_value) missing_flag=1;missing_count=float(missing_flag.total())/missing_flag.size();print(missing_count)' stomate_restart.nc  ~/foo.nc
+ ncap2 -O -s 'missing_flag[$y,$x]=0;where(t2m_daily!=t2m_daily@missing_value) missing_flag=1;missing_count=float(missing_flag.total($x))/missing_flag.size($x);print(missing_count)' stomate_restart.nc  ~/foo.nc
+</code>
+
+
+== cdo ==
+
+A command that handle many operations one would like to do when working on outputs of models of the Earth System :
+  * changing of time axis
+  * regridding (many grid are already implemented and it is an even more versatile tool)
+  * complex operations...
+
+See the website of the project {{https://code.zmaw.de/projects/cdo/wiki}} or the doc : {{:reunions_orchidee:cdo-manual.pdf| CDO Manual}} and  the  {{:reunions_orchidee:cdo_refcard.pdf | quickref}}
+
+<code>
+cdo -v # print list of available operators
+cdo -V # version (if very old, think of downloading the source and install a new version, as it is a tool that is evolving quickly
+cdo -h remapcon # informations about a command
+cdo remapcon,my_grid my_climatology.nc my_regridded_climatology.nc # conservative regridding to an other resolution
+</code>
+
+my_grid could be a file like :<code>
+gridtype  = lonlat
+gridsize  = 220
+xname     = longitude
+xunits    = degrees_east
+yname     = latitude
+yunits    = degrees_north
+xsize     = 20
+ysize     = 11
+xfirst    = -18.75
+xinc      = 3.75
+yfirst    = 20