extract a (vertical, time) slice from a netCDF

extract.sh

#!/usr/bin/env bash

set -e

display_usage() {
	echo "Extract a slice from a netCDF and remove the variable"
	echo "extract.sh [in] [dimension] [value] [out]"
	echo ""
	echo "Example: extract.sh temperature.nc elevation 2 temperature_2.nc"
}

if [ $# -ne 4 ]
then
	display_usage
	exit 1
fi

N=1

TEMP1=`mktemp -u --suffix=.nc`
TEMP2=`mktemp -u --suffix=.nc`
TEMP3=`mktemp -u --suffix=.nc`

ncea -d ${2},${N},${N} -F ${1} ${TEMP1}
# Drop the time dimension
ncwa --no_tmp_fl -h -a ${2} ${TEMP1} ${TEMP2}
# Drop the time variable
ncks --no_tmp_fl -h -C -O -x -v ${2} ${TEMP2} ${TEMP3}

mv ${TEMP3} ${4}

rm ${TEMP1}
rm ${TEMP2}