GEOS-5

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== CDO ==
== Climate Data Operators (CDO) ==


Possible example uses of CDO are:
As stated by their creators, the [https://code.zmaw.de/projects/cdo Climate Data Operators] (CDO) are:


=== Display info about a file ===
CDO is a collection of command line Operators to manipulate and analyse Climate and NWP model Data.


=== Diff two files ===
=== Where to find CDO ===


=== Extract variable(s) from a file ===
==== NCCS ====


=== Extract time(s) from a file ===
Users can access CDO in a variety of ways. On discover, the easiest way is to load the cdo module:


To extract a single (or multiple) year from a multi-step file, you can use <tt>selyear</tt>,''year'':
module load other/cdo
 
It is also included in GMAO-Baselibs-4_0_0 and higher (corresponds to Ganymed-3_0 or newer). It will be located at
 
$BASEDIR/Linux/bin/cdo
 
once <tt>g5_modules</tt> is sourced.
 
==== NAS ====
 
At NAS, there are a couple options. First, it is available through Baselibs as above. You can also access a portable version (compiled with system gcc) at
 
/nobackup/gmao_SIteam/Utilities/bin/cdo
 
As this is completely portable, you can also copy this to a local <tt>bin</tt> directory if desired.
 
==== GSFC Desktops ====
 
If you are on a GMAO desktop and have access to <tt>/ford1</tt>, there is a version at
 
/ford1/local/EL6-64/bin/cdo
 
as well as at:
 
/ford1/share/gmao_SIteam/Utilities/bin/cdo
 
The <tt>/ford1/share</tt> version could be more bleeding-edge than the <tt>/ford1/local</tt> version as it will usually be whatever version is in the latest Baselibs tag.
 
=== Example Uses of CDO ===
 
==== Display info about a file ====
 
CDO offers many operators that provide information about a file. The most important two are '''infon''' and '''sinfon'''. Note the '''n''' at the end: that means "display variable names". If you don't provide that, you'll still get information, but it'll be for variables -1, -2, -3, etc.
 
===== Short Information =====
 
If you just want a summary of what's in the file, use '''sinfon''':
 
$ cdo '''sinfon''' stock-G40U-Intel11-2013Jun10-1day-c48.geosgcm_moist.20000415_0900z.nc4
  File format: netCDF4
    -1 : Institut Source  Ttype    Levels Num  Gridsize Num Dtype : Parameter name
    1 : unknown  unknown  instant      48  1    16380  1  F32  : CLCN     
    2 : unknown  unknown  instant      48  1    16380  1  F32  : CLLS     
    3 : unknown  unknown  instant      48  1    16380  1  F32  : CNVMF0   
    4 : unknown  unknown  instant      48  1    16380  1  F32  : CNVMFC   
    5 : unknown  unknown  instant      48  1    16380  1  F32  : CNVMFD   
    6 : unknown  unknown  instant      48  1    16380  1  F32  : EVAPC     
    7 : unknown  unknown  instant      48  1    16380  1  F32  : FCLD     
    8 : unknown  unknown  instant      1  2    16380  1  F32  : PHIS     
    9 : unknown  unknown  instant      48  1    16380  1  F32  : QI       
    10 : unknown  unknown  instant      48  1    16380  1  F32  : QICN     
    11 : unknown  unknown  instant      48  1    16380  1  F32  : QILS     
    12 : unknown  unknown  instant      48  1    16380  1  F32  : QL       
    13 : unknown  unknown  instant      48  1    16380  1  F32  : QLCN     
    14 : unknown  unknown  instant      48  1    16380  1  F32  : QLLS     
    15 : unknown  unknown  instant      48  1    16380  1  F32  : QR       
    16 : unknown  unknown  instant      48  1    16380  1  F32  : REVAN     
    17 : unknown  unknown  instant      48  1    16380  1  F32  : REVCN     
    18 : unknown  unknown  instant      48  1    16380  1  F32  : REVLS     
    19 : unknown  unknown  instant      48  1    16380  1  F32  : RH1       
    20 : unknown  unknown  instant      48  1    16380  1  F32  : RICE     
    21 : unknown  unknown  instant      48  1    16380  1  F32  : RLIQ     
    22 : unknown  unknown  instant      48  1    16380  1  F32  : RSUAN     
    23 : unknown  unknown  instant      48  1    16380  1  F32  : RSUCN     
    24 : unknown  unknown  instant      48  1    16380  1  F32  : RSULS     
    25 : unknown  unknown  instant      48  1    16380  1  F32  : SUBLC     
    26 : unknown  unknown  instant      48  1    16380  1  F32  : THIM     
  Grid coordinates :
    1 : lonlat      > size      : dim = 16380  nlon = 180  nlat = 91
                        lon      : first = -180  last = 178  inc = 2  degrees_east  circular
                        lat      : first = -90  last = 90  inc = 2  degrees_north
  Vertical coordinates :
    1 : pressure            hPa : 1000 975 950 925 900 875 850 825 800 775 750 725
                                    700 650 600 550 500 450 400 350 300 250 200 150
                                    100 70 50 40 30 20 10 7 5 4 3 2 1 0.699999988 0.5
                                    0.400000006 0.300000012 0.200000003 0.100000001
                                    0.0700000003 0.0500000007 0.0399999991 0.0299999993
                                    0.0199999996
    2 : surface                  : 0
  Time coordinate :  1 step
    RefTime =  2000-04-15 09:00:00  Units = minutes  Calendar = STANDARD
  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss
  2000-04-15 09:00:00
cdo sinfon: Processed 26 variables over 1 timestep ( 0.02s )
 
===== Information and Simple Statistics =====
 
The other operator, '''infon''', provides more information and some useful statistics:
 
$ cdo infon stock-G40U-Intel11-2013Jun10-1day-c48.geosgcm_moist.20000415_0900z.nc4
    -1 :      Date    Time  Level Gridsize    Miss :    Minimum        Mean    Maximum : Parameter name
    1 : 2000-04-15 09:00:00    1000    16380    7283 :      0.0000  0.00055663    0.053927 : CLCN     
    2 : 2000-04-15 09:00:00    975    16380    3443 :      0.0000  0.0053316    0.19191 : CLCN     
    3 : 2000-04-15 09:00:00    950    16380    2381 :      0.0000    0.021698    0.52759 : CLCN     
    4 : 2000-04-15 09:00:00    925    16380    2008 :      0.0000    0.046928    0.62649 : CLCN     
    5 : 2000-04-15 09:00:00    900    16380    1730 :      0.0000    0.068160    0.76086 : CLCN     
    6 : 2000-04-15 09:00:00    875    16380    1488 :      0.0000    0.083106    0.78922 : CLCN     
    7 : 2000-04-15 09:00:00    850    16380    1340 :      0.0000    0.082435    0.85127 : CLCN     
    8 : 2000-04-15 09:00:00    825    16380    1216 :      0.0000    0.064390    0.79455 : CLCN     
    9 : 2000-04-15 09:00:00    800    16380    1135 :      0.0000    0.049025    0.67987 : CLCN     
    10 : 2000-04-15 09:00:00    775    16380    1024 :      0.0000    0.039010    0.71728 : CLCN     
    11 : 2000-04-15 09:00:00    750    16380    927 :      0.0000    0.033034    0.67065 : CLCN     
    12 : 2000-04-15 09:00:00    725    16380    800 :      0.0000    0.028919    0.82533 : CLCN     
    13 : 2000-04-15 09:00:00    700    16380    680 :      0.0000    0.025265    0.71002 : CLCN     
    14 : 2000-04-15 09:00:00    650    16380    161 :      0.0000    0.023027    0.60691 : CLCN     
    15 : 2000-04-15 09:00:00    600    16380      21 :      0.0000    0.029113    0.79990 : CLCN     
    16 : 2000-04-15 09:00:00    550    16380      2 :      0.0000    0.031865    0.86731 : CLCN     
    17 : 2000-04-15 09:00:00    500    16380      0 :      0.0000    0.021714    0.86754 : CLCN     
    18 : 2000-04-15 09:00:00    450    16380      0 :      0.0000    0.016821    0.80432 : CLCN     
    19 : 2000-04-15 09:00:00    400    16380      0 :      0.0000    0.017517    0.82690 : CLCN     
    20 : 2000-04-15 09:00:00    350    16380      0 :      0.0000    0.029577    0.84485 : CLCN     
    21 : 2000-04-15 09:00:00    300    16380      0 :      0.0000    0.037508    0.84544 : CLCN     
    22 : 2000-04-15 09:00:00    250    16380      0 :      0.0000    0.048294    0.80001 : CLCN     
    23 : 2000-04-15 09:00:00    200    16380      0 :      0.0000    0.053185    0.77885 : CLCN     
    24 : 2000-04-15 09:00:00    150    16380      0 :      0.0000    0.035487    0.83891 : CLCN     
    25 : 2000-04-15 09:00:00    100    16380      0 :      0.0000  0.00044752    0.19931 : CLCN     
    26 : 2000-04-15 09:00:00      70    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    27 : 2000-04-15 09:00:00      50    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    28 : 2000-04-15 09:00:00      40    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    29 : 2000-04-15 09:00:00      30    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    30 : 2000-04-15 09:00:00      20    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    31 : 2000-04-15 09:00:00      10    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    32 : 2000-04-15 09:00:00      7    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    33 : 2000-04-15 09:00:00      5    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    34 : 2000-04-15 09:00:00      4    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    35 : 2000-04-15 09:00:00      3    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    36 : 2000-04-15 09:00:00      2    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    37 : 2000-04-15 09:00:00      1    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    38 : 2000-04-15 09:00:00    0.7    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    39 : 2000-04-15 09:00:00    0.5    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    40 : 2000-04-15 09:00:00    0.4    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    41 : 2000-04-15 09:00:00    0.3    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    42 : 2000-04-15 09:00:00    0.2    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    43 : 2000-04-15 09:00:00    0.1    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    44 : 2000-04-15 09:00:00    0.07    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    45 : 2000-04-15 09:00:00    0.05    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    46 : 2000-04-15 09:00:00    0.04    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    47 : 2000-04-15 09:00:00    0.03    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    48 : 2000-04-15 09:00:00    0.02    16380      0 :      0.0000      0.0000      0.0000 : CLCN     
    49 : 2000-04-15 09:00:00    1000    16380    7283 :      0.0000    0.019079    0.97125 : CLLS     
    50 : 2000-04-15 09:00:00    975    16380    3443 :      0.0000    0.068198    0.94812 : CLLS     
    51 : 2000-04-15 09:00:00    950    16380    2381 :      0.0000    0.083635    0.93380 : CLLS     
    52 : 2000-04-15 09:00:00    925    16380    2008 :      0.0000    0.096190    0.83637 : CLLS     
...
 
As you can see, you not only get information, but statistics. It provides the number of values on the grid, <tt>Gridsize</tt>; the number of Missing Values, <tt>Miss</tt>; and the <tt>Minimum</tt>, <tt>Mean</tt>, and <tt>Maximum</tt> for each <tt>Level</tt> for each value.
 
==== Diff two files ====
 
One of the main reasons CDO is attractive is for diffing two files. With binary files, such as the old restarts, one could use <tt>cmp</tt> or <tt>diff</tt> to check for differences. However, <tt>cmp</tt> will not work on NetCDF files because while the data might be the same, the metadata surely won't:
 
$ cmp stock-G40U-Intel11-2013Jun10-1day-c48.geosgcm_moist.20000415_0900z.nc4 \
      mat-WW3-G40U-2013Jun10-NOWAVE-1day-c48.geosgcm_moist.20000415_0900z.nc4
stock-G40U-Intel11-2013Jun10-1day-c48.geosgcm_moist.20000415_0900z.nc4 \
  mat-WW3-G40U-2013Jun10-NOWAVE-1day-c48.geosgcm_moist.20000415_0900z.nc4 differ: byte 55, line 4
 
 
There already is a tool for doing this with HDF5/NetCDF4 files: <tt>h5diff</tt>. However, <tt>h5diff</tt> is slow (at least the version we have):
 
$ time h5diff stock-G40U-Intel11-2013Jun10-1day-c48.geosgcm_moist.20000415_0900z.nc4 \
              mat-WW3-G40U-2013Jun10-NOWAVE-1day-c48.geosgcm_moist.20000415_0900z.nc4
attribute: <Title of </>> and <Title of </>>
37 differences found
0.116u 0.412s '''0:44.38''' 1.1% 0+0k 0+0io 0pf+0w
 
CDO, however, seems to be much more efficient at doing diff comparisons:
 
$ time cdo diffn stock-G40U-Intel11-2013Jun10-1day-c48.geosgcm_moist.20000415_0900z.nc4 \
                  mat-WW3-G40U-2013Jun10-NOWAVE-1day-c48.geosgcm_moist.20000415_0900z.nc4
  0 of 1201 records differ
cdo diffn: Processed 39344760 values from 52 variables over 2 timesteps ( 0.49s )
0.424u 0.068s '''0:04.28''' 11.2% 0+0k 0+0io 0pf+0w
 
Of course, 44 seconds v 4 seconds isn't much (and with smaller files, GPFS can sometimes 'cache' the files making it seem fast), but with c360, things get inflated. Let's diff two c360 NetCDF4 fvcore_internal_rst files:
 
$ time h5diff fvcore_internal_rst.control.nc4 fvcore_internal_rst.test.nc4
3.188u 6.824s '''14:57.19''' 1.1% 0+0k 400+0io 0pf+0w
$ time cdo diffn fvcore_internal_rst.control.nc4 fvcore_internal_rst.test.nc4
  0 of 505 records differ
cdo diffn: Processed 785376000 values from 14 variables over 2 timesteps ( 18.76s )
17.125u 1.648s '''2:33.97''' 12.1% 0+0k 0+0io 0pf+0w
 
This tells us two things, the <tt>h5diff</tt> we have to use is slow and one should develop at lower-resolution if diffing restarts is part of your process.
 
==== Behavior when two files differ ====
 
All the above examples show two files that don't differ. If they do differ, CDO provides additional useful information like:
 
          For each pair of fields the operator prints one line with the following information:
          - Date and Time
          - Level, Gridsize and number of Missing values
          - Occurrence of coefficient pairs with different signs (S)
          - Occurrence of zero values (Z)
          - Maxima of absolute difference of coefficient pairs
          - Maxima of relative difference of non-zero coefficient pairs with equal signs
          - Parameter name
 
as seen here:
 
$ cdo diffn stock-G40U-CPU-2013Jun11-6hour-144.geosgcm_prog.20000415_0000z.nc4 stock-G40U-GPU-2013Jun11-6hour-144.geosgcm_prog.20000415_0000z.nc4
              Date    Time  Level Gridsize    Miss : S Z  Max_Absdiff Max_Reldiff : Parameter name
    1 : 2000-04-15 00:00:00    1000    13104    5606 : F T      0.64627    0.041020 : H         
    2 : 2000-04-15 00:00:00    975    13104    3202 : F F      0.64383    0.19488 : H         
    3 : 2000-04-15 00:00:00    950    13104    2394 : F F      0.64948  0.0014438 : H         
    4 : 2000-04-15 00:00:00    925    13104    2047 : F F      0.65057  0.00083438 : H         
    5 : 2000-04-15 00:00:00    900    13104    1793 : F F      0.67102  0.00067943 : H         
    6 : 2000-04-15 00:00:00    875    13104    1555 : F F      0.66370  0.00058364 : H         
    7 : 2000-04-15 00:00:00    850    13104    1401 : F F      0.65869  0.00043395 : H         
    8 : 2000-04-15 00:00:00    825    13104    1305 : F F      0.64941  0.00036629 : H         
    9 : 2000-04-15 00:00:00    800    13104    1188 : F F      0.63110  0.00033837 : H         
...snip...
  477 : 2000-04-15 00:00:00    0.2    13104      0 : F F    0.019527    0.32925 : V         
  478 : 2000-04-15 00:00:00    0.1    13104      0 : F F    0.059674    0.77863 : V         
  479 : 2000-04-15 00:00:00    0.07    13104      0 : F F    0.057358    0.46071 : V         
  480 : 2000-04-15 00:00:00    0.05    13104      0 : T F    0.021697    0.74741 : V         
  481 : 2000-04-15 00:00:00    0.04    13104      0 : T F    0.021576    0.40354 : V         
  482 : 2000-04-15 00:00:00    0.03    13104      0 : F F    0.020691    0.34921 : V         
  483 : 2000-04-15 00:00:00    0.02    13104      0 : T F    0.020302    0.62736 : V         
  438 of 483 records differ
  389 of 483 records differ more than 0.001
cdo diffn: Processed 12658464 values from 26 variables over 2 timesteps ( 0.17s )
$ echo $?
0
 
''''NOTE'''': CDO returns a status of 0 any time it doesn't encounter an error. Thus, if two files are different, CDO will report differences, but the return status will still be 0 as cdo technically completed successfully as seen above. Thus, any tests you might have that depend on the return of cmp for binary need to be altered for NetCDF4. One possible formulation is:
 
set NUMDIFF = `cdo -s diffn | grep differ | awk '{print $1}'`
if ( $NUMDIFF == 0 ) then
  success
else
  failure
endif
 
==== Extract fields(s) from a file ====
 
===== Extract variable(s) from a file =====
 
Often, our NetCDF4 files have many variables and we only care about one. CDO allows one to extract or ''select'' one or more variables. For example, if you only want CLCN, use '''selname''':
 
$ cdo '''selname,CLCN''' mat-WW3-G40U-2013Jun10-NOWAVE-1day-c48.geosgcm_moist.20000415_0900z.nc4 onlyclcn.nc4
cdo selname: Processed 786240 values from 26 variables over 1 timestep ( 0.03s )
$ cdo sinfon onlyclcn.nc4
  File format: netCDF4
    -1 : Institut Source  Ttype    Levels Num  Gridsize Num Dtype : Parameter name
    1 : unknown  unknown  instant      48  1    16380  1  F32  : CLCN     
  Grid coordinates :
    1 : lonlat      > size      : dim = 16380  nx = 180  ny = 91
                        lon      : first = -180  last = 178  inc = 2  degrees_east  circular
                        lat      : first = -90  last = 90  inc = 2  degrees_north
  Vertical coordinates :
    1 : pressure            hPa : 1000 975 950 925 900 875 850 825 800 775 750 725
                                    700 650 600 550 500 450 400 350 300 250 200 150
                                    100 70 50 40 30 20 10 7 5 4 3 2 1 0.699999988 0.5
                                    0.400000006 0.300000012 0.200000003 0.100000001
                                    0.0700000003 0.0500000007 0.0399999991 0.0299999993
                                    0.0199999996
  Time coordinate :  1 step
    RefTime =  2000-04-15 09:00:00  Units = minutes  Calendar = standard
  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss
  2000-04-15 09:00:00
cdo sinfon: Processed 1 variable over 1 timestep ( 0.00s )
 
===== Extract time(s) from a file =====
 
To extract a single (or multiple) year from a multi-step file, you can use <tt>selyear</tt>,''year''. For multiple years, you can either do <tt>cdo '''selyear,1999,2000,2001'''</tt> or <tt>cdo '''selyear,1999/2001'''</tt>.


  $ cdo sinfon pchem.species.CMIP-5.1870-2097.z_91x72.nc4
  $ cdo sinfon pchem.species.CMIP-5.1870-2097.z_91x72.nc4
Line 100: Line 364:
  cdo sinfon: Processed 7 variables over 36 timesteps ( 0.00s )
  cdo sinfon: Processed 7 variables over 36 timesteps ( 0.00s )


== tkcvs ==
===== Other select operators =====
CDO has many of these operators:
 
  selparam Select parameters by identifier
  delparam Delete parameters by identifier
  selcode Select parameters by code number
  delcode Delete parameters by code number
  selname Select parameters by name
  delname Delete parameters by name
  selstdname Select parameters by standard name
  sellevel Select levels
  sellevidx Select levels by index
  selgrid Select grids
  selzaxis Select z-axes
  selltype Select GRIB level types
  seltabnum Select parameter table numbers
  seltimestep Select timesteps
  seltime Select times
  selhour Select hours
  selday Select days
  selmon Select months
  selyear Select years
  selseas Select seasons
  seldate Select dates
  selsmon Select single month
  sellonlatbox Select a longitude/latitude box
  selindexbox Select an index box
 
==== Combining Operators ====
 
Often, you want to do multiple operations on a file. You could, say, do a '''selname''' and output only one variable to a file, then a '''sellevel''' on that new file to select a single level, and then a '''selyear''' on ''that'', etc.:
 
$ cdo '''selname,OX''' pchem.species.CMIP-5.1870-2097.z_91x72.nc4 onlyOX.nc4
cdo selname: Processed 17926272 values from 7 variables over 2736 timesteps ( 9.60s )
$ cdo '''sellevel,1.5''' onlyOX.nc4 onlyOX.only1.5.nc4
cdo sellevel: Processed 248976 values from 1 variable over 2736 timesteps ( 0.76s )
$ cdo '''selyear,1999''' onlyOX.only1.5.nc4 onlyOX.only1.5.only1999.nc4
cdo selyear: Processed 1092 values from 1 variable over 2736 timesteps ( 0.05s )
$ cdo sinfon onlyOX.only1.5.only1999.nc4
  File format: netCDF4
    -1 : Institut Source  Ttype    Levels Num  Gridsize Num Dtype : Parameter name
    1 : unknown  http://geos5.org/wiki/index.php?title=GEOS-5_Configuration_for_AR5 instant      1  1        91  1  F32  : OX       
  Grid coordinates :
    1 : lonlat      > size      : dim = 91  nx = 0  ny = 91
                        lat      : first = -1.57079637  last = 1.57079625  inc = 0.0349065065  radians
  Vertical coordinates :
    1 : generic            layer : 1.5
  Time coordinate :  12 steps
    RefTime =  1870-01-15 12:00:00  Units = hours  Calendar = standard
  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss
  1999-01-14 22:00:00  1999-02-14 08:00:00  1999-03-16 18:00:00  1999-04-16 04:00:00
  1999-05-16 14:00:00  1999-06-16 00:00:00  1999-07-16 10:00:00  1999-08-15 20:00:00
  1999-09-15 06:00:00  1999-10-15 16:00:00  1999-11-15 02:00:00  1999-12-15 12:00:00
cdo sinfon: Processed 1 variable over 12 timesteps ( 0.00s )
 
Of course, this is not only annoying, but wasteful as you are creating many temporary files. Instead, CDO allows one to "combine" or "chain" operators. This is done by using -operator:
 
  cdo -L operatorN -operatorN-1 ... -operator2 -operator1 input (output)
 
The -L is used because HDF5 isn't thread-safe as currently compiled. This "locks" I/O preventing an issue. We are working on trying to get CDO to work in parallel better.
 
So, doing the above operator in one step:
 
$ cdo -L selyear,1999 -sellevel,1.5 -selname,OX pchem.species.CMIP-5.1870-2097.z_91x72.nc4 onlyOX-1.5-1999.nc4
cdo selyear: Started child process "sellevel,1.5 -selname,OX pchem.species.CMIP-5.1870-2097.z_91x72.nc4 (pipe1.1)".
cdo(2) sellevel: Started child process "selname,OX pchem.species.CMIP-5.1870-2097.z_91x72.nc4 (pipe2.1)".
cdo(3) selname: Processed 17926272 values from 7 variables over 2736 timesteps ( 3.18s )
cdo(2) sellevel: Processed 248976 values from 1 variable over 2736 timesteps ( 3.18s )
cdo selyear: Processed 1092 values from 1 variable over 2736 timesteps ( 3.18s )
$ cdo sinfon onlyOX-1.5-1999.nc4
  File format: netCDF4
    -1 : Institut Source  Ttype    Levels Num  Gridsize Num Dtype : Parameter name
    1 : unknown  http://geos5.org/wiki/index.php?title=GEOS-5_Configuration_for_AR5 instant      1  1        91  1  F32  : OX       
  Grid coordinates :
    1 : lonlat      > size      : dim = 91  nx = 0  ny = 91
                        lat      : first = -1.57079637  last = 1.57079625  inc = 0.0349065065  radians
  Vertical coordinates :
    1 : generic            layer : 1.5
  Time coordinate :  12 steps
    RefTime =  1870-01-15 12:00:00  Units = hours  Calendar = standard
  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss
  1999-01-14 22:00:00  1999-02-14 08:00:00  1999-03-16 18:00:00  1999-04-16 04:00:00
  1999-05-16 14:00:00  1999-06-16 00:00:00  1999-07-16 10:00:00  1999-08-15 20:00:00
  1999-09-15 06:00:00  1999-10-15 16:00:00  1999-11-15 02:00:00  1999-12-15 12:00:00
cdo sinfon: Processed 1 variable over 12 timesteps ( 0.00s )
 
This file is the same as the one done in three steps:
 
$ cdo diffn onlyOX.only1.5.only1999.nc4 onlyOX-1.5-1999.nc4
  0 of 12 records differ
cdo diffn: Processed 2184 values from 2 variables over 24 timesteps ( 0.00s )
 
Of course, you could even do the '''diffn''' as well in the command:
 
$ cdo -L diffn -selyear,1999 -sellevel,1.5 -selname,OX pchem.species.CMIP-5.1870-2097.z_91x72.nc4 onlyOX.only1.5.only1999.nc4
cdo diffn: Started child process "selyear,1999 -sellevel,1.5 -selname,OX pchem.species.CMIP-5.1870-2097.z_91x72.nc4 (pipe1.1)".
cdo(2) selyear: Started child process "sellevel,1.5 -selname,OX pchem.species.CMIP-5.1870-2097.z_91x72.nc4 (pipe2.1)".
cdo(3) sellevel: Started child process "selname,OX pchem.species.CMIP-5.1870-2097.z_91x72.nc4 (pipe3.1)".
  0 of 12 records differ
cdo(4) selname: Processed 17926272 values from 7 variables over 2736 timesteps ( 3.13s )
cdo(3) sellevel: Processed 248976 values from 1 variable over 2736 timesteps ( 3.13s )
cdo(2) selyear: Processed 1092 values from 1 variable over 2736 timesteps ( 3.13s )
cdo diffn: Processed 2184 values from 2 variables over 24 timesteps ( 3.13s )
 
Note: if you don't want the extraneous information, use '''-s''' to enable '''silent''' mode:
 
cdo -s -L diffn -selyear,1999 -sellevel,1.5 -selname,OX pchem.species.CMIP-5.1870-2097.z_91x72.nc4 onlyOX.only1.5.only1999.nc4
  0 of 12 records differ
 
== TkCVS ==
 
The main website for TkCVS can be found [http://www.twobarleycorns.net/tkcvs.html here].
 
On discover, you can use TkCVS by loading the <tt>other/tkcvs-8.2.3</tt> module:
 
module load other/tkcvs-8.2.3


== ack ==
== ack ==


The main website for ack can be found [http://beyondgrep.com/ here].
If you'd like to try ack out, you can run:
  curl http://beyondgrep.com/ack-2.04-single-file > ~/bin/ack && chmod 0755 !#:3
and it will install ack for you in your local bin directory.


[[Category:SI Team]]
[[Category:SI Team]]
[[Category:Brown Bags]]
[[Category:Brown Bags]]
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