Fixing spatial subsetting coverage (#66)

The problem of not fully covering subsetted areas is resolved with this
PR. The basic idea as expanding the required spatial extends by the
resolution of the datset, i.e., 0.25 degree.

Reported-by: Hongli Liu <[email protected]>

Signed-off-by: Kasra Keshavarz <[email protected]>

Author: kasra-keshavarz

scripts/ecmwf-era5/era5_simplified.sh

@@ -98,6 +98,8 @@ if [[ -z $prefix ]]; then
   prefix="data_"
 fi
 
+# useful log date format function
+logDate () { echo "($(date +"%Y-%m-%d %H:%M:%S")) "; }
 
 # =====================
 # Necessary assumptions
@@ -156,16 +158,29 @@ lims_to_float () { IFS=',' read -ra l <<< $@; f_arr=(); for i in "${l[@]}"; do f
 # Data processing
 # ===============
 # display info
-echo "$(basename $0): processing ECMWF ERA5..."
+echo "$(logDate)$(basename $0): processing ECMWF ERA5..."
 
 # make the output directory
-echo "$(basename $0): creating output directory under $outputDir"
+echo "$(logDate)$(basename $0): creating output directory under $outputDir"
 mkdir -p "$outputDir"
 
+# take care of dates
 toDate="$startDate"
 toDateUnix="$(unix_epoch "$toDate")"
 endDateUnix="$(unix_epoch "$endDate")"
 
+# parse the upper and lower bounds of a given spatial limit
+minLat=$(lims_to_float $latLims | cut -d ',' -f 1)
+maxLat=$(lims_to_float $latLims | cut -d ',' -f 2)
+minLon=$(lims_to_float $lonLims | cut -d ',' -f 1)
+maxLon=$(lims_to_float $lonLims | cut -d ',' -f 2)
+
+# adding/subtracting 0.1 degree to/from max/min values
+minLat=$(bc <<< "$minLat - 0.25")
+maxLat=$(bc <<< "$maxLat + 0.25")
+minLon=$(bc <<< "$minLon - 0.25")
+maxLon=$(bc <<< "$maxLon + 0.25")
+
 # creating yearly directory
 mkdir -p "$outputDir" # making the output directory
 
@@ -177,13 +192,17 @@ while [[ "$toDateUnix" -le "$endDateUnix" ]]; do
   # creating file name
   file="${fileStruct}_${toDateFormatted}.nc" # current file name
 
+  # wait to be trapped
+  trap 'wait' CHLD
+
   # extracting variables from the files and spatial subsetting
-  ncks -O -v "$variables" \
-          -d latitude,"$(lims_to_float "$latLims")" \
-          -d longitude,"$(lims_to_float "$lonLims")" \
-          "${datasetDir}/${file}" "${outputDir}/${prefix}${file}"
+  (ncks -O -v "$variables" \
+       -d latitude,"${minLat},${maxLat}" \
+       -d longitude,"${minLon},${maxLon}" \
+       "${datasetDir}/${file}" "${outputDir}/${prefix}${file}") &
 
-  [ $( jobs | wc -l ) -ge $( nproc ) ] && wait # forking shell processes
+  # make sure ncks finishes
+  wait $!
 
   # increment time-step by one unit
   toDate="$(date --date "$toDate 1month")" # current time-step
@@ -198,6 +217,6 @@ if [[ "$toDateUnix" == "$endOfCurrentYearUnix" ]]; then
   toDate=$(date --date "$toDate 1month")
 fi
 
-
-echo "$(basename $0): results are produced under $outputDir."
+# exit message
+echo "$(logDate)$(basename $0): results are produced under $outputDir."