Kokron, Daniel S. Thu, 6 Sep 2012 20:15:31 -0500
>> Have a look at the 'grdinfo' utility which is part of GMT5.
>> http://www.soest.hawaii.edu/gmt5/
GMT looks interesting (and is available as a debian package) but
`grdinfo` seems to only work with 2d data (Am I missing something?)
E.g., for
$ ncdump -h ./GEIA_N2O_oceanic.nc
> netcdf GEIA_N2O_oceanic {
> dimensions:
> lon = 360 ;
> lat = 180 ;
> time = UNLIMITED ; // (1 currently)
> variables:
...
> double emi_n2o(time, lat, lon) ;
> emi_n2o:units = "ton N2O-N/yr" ;
> emi_n2o:missing_value = -999. ;
> emi_n2o:long_name = "N2O emissions" ;
> emi_n2o:_FillValue = -999.f ;
...
$ GMT grdinfo ./GEIA_N2O_oceanic.nc
> grdinfo: No 2-D variable in file [./GEIA_N2O_oceanic.nc]
Alas.
Charlie Zender Fri, 07 Sep 2012 10:16:19 -0700
> Your query matches a category of commands which I call filters[,
> e.g.] http://nco.sf.net/nco.html#filters [. Since] ncap2 [is]
> better for arbitrarily complex and longer filters
... I went with that, even though the bigot in me rails against the
requirement to write a file as a side effect. (Fortunately he was
appeased by use of tempfiles :-) `source`able bash follows my .sig.
your assistance is appreciated, Tom Roche <Tom_Roche@xxxxxxxxx>
---------------------code follows to end of post---------------------
# bash functions for NCO "filters", as suggested by Charlie Zender @
#
http://www.unidata.ucar.edu/mailing_lists/archives/netcdfgroup/2012/msg00286.html
# http://nco.sourceforge.net/nco.html#filters
# All use `ncap2` and take input like $1=datavar name, $2=filename
# Prints maximum
function ncmax {
TMPFILE="$(mktemp)"
ncap2 -O -C -v -s "foo=${1}.max();print(foo)" ${2} ${TMPFILE} | cut -f 3- -d
' '
}
function ncmin {
TMPFILE="$(mktemp)"
ncap2 -O -C -v -s "foo=${1}.min();print(foo)" ${2} ${TMPFILE} | cut -f 3- -d
' '
}
# Prints mean
function ncmean {
TMPFILE="$(mktemp)"
ncap2 -O -C -v -s "foo=${1}.avg();print(foo)" ${2} ${TMPFILE} | cut -f 3- -d
' '
}
# median not currently available?
# Prints RMS (root-mean-square, normalized by N)
function ncRMS {
TMPFILE="$(mktemp)"
ncap2 -O -C -v -s "foo=${1}.rms();print(foo)" ${2} ${TMPFILE} | cut -f 3- -d
' '
}
# Prints range (of values in datavar)
function ncrange {
TMPFILE="$(mktemp)"
ncap2 -O -C -v -s \
"foo=${1}.min();bar=${1}.max();print(foo,\"%f\");print(\" to
\");print(bar,\"%f\")"\
${2} ${TMPFILE}
}
# Prints number of elements in datavar (including NA)
function ncsize {
TMPFILE="$(mktemp)"
ncap2 -O -C -v -s "foo=${1}.size();print(foo)" ${2} ${TMPFILE} | cut -f 3- -d
' '
}
# Prints total
function nctotal {
TMPFILE="$(mktemp)"
ncap2 -O -C -v -s "foo=${1}.total();print(foo)" ${2} ${TMPFILE} | cut -f 3-
-d ' '
}
