[Dart-dev] DART/branches Revision: 12538

[dart at ucar.edu]

nancy at ucar.edu
2018-04-19 09:11:51 -0600 (Thu, 19 Apr 2018)
256
split up a daily obs_seq file into 10 minute chunks.
the chunk size is settable in this script.
currently makes output files of the filename pattern:
obs_seqYYYYMMDDHHMM
but that can be easily changed to be whatever is
easiest to handle in the scripting.




Added: DART/branches/openggcm/observations/obs_converters/gps/shell_scripts/split_obs_seq.csh
===================================================================
--- DART/branches/openggcm/observations/obs_converters/gps/shell_scripts/split_obs_seq.csh	                        (rev 0)
+++ DART/branches/openggcm/observations/obs_converters/gps/shell_scripts/split_obs_seq.csh	2018-04-19 15:11:51 UTC (rev 12538)
@@ -0,0 +1,111 @@
+#!/bin/csh
+#
+# DART software - Copyright UCAR. This open source software is provided
+# by UCAR, "as is", without charge, subject to all terms of use at
+# http://www.image.ucar.edu/DAReS/DART/DART_download
+#
+# DART $Id$
+
+# Example of a shell script to split a series of obs_sequence files
+# into a series of multiple smaller files.  It requires the 'advance_time'
+# executable to do the time/calendar computations, and it will almost
+# certainly require some customization for use with any input other
+# than our NCEP daily obs_seq files.  But it should be a good starting
+# point for additional scripting. Thanks to Josh Hacker for contributing it.
+#
+# Split a series of obs_sequence files into multiple smaller files.
+# This depends on knowing how the original files are organized, e.g. are
+# the observations one file per day from 0Z to 0Z, or they are one
+# file per day but 3Z to 3Z as our NCEP obs files are organized (so
+# 6 hour assimilation windows centered on 6,12,18,24Z can be run 
+# from a single input file).   The cycle interval below should be
+# an exact multiple of the length of the input files.
+# (This script is set up for the daily 3Z to 3Z arrangement.)
+
+# set start and end YYYYMMDDHHMM here. 
+# this is the midpoint of each time window.
+set starth = 201303170000
+set   endh = 201303170200
+
+# set time window for each output file.  the syntax of these
+# lines must match the valid input formats for the advance_time program
+set cycle_interval = 10m      # total interval duration
+set first_half     = -5m+1s  # -half interval + 1 second
+set last_half      = +5m     # +half interval
+
+
+# set once and should be able to leave as-is
+set output_dir   = ./data
+set advance_exec = ./advance_time
+set nml_template = ./input.nml.template
+set COPY         = "/bin/cp -f"
+set MOVE         = "/bin/mv -f"
+
+
+# loop from start to end time.
+set dtg = $starth
+while ( $dtg <= $endh )
+  
+  echo processing window centered on time $dtg 
+  set start_window=(`echo $dtg ${first_half} -g | $advance_exec`)
+  set start_day = $start_window[1]
+  set start_sec = $start_window[2]
+  set end_window=(`echo $dtg ${last_half} -g | $advance_exec`)
+  set end_day = $end_window[1]
+  set end_sec = $end_window[2]
+
+  # use time string to construct unique output file names
+  set filn_out = ${output_dir}/obs_seq$dtg
+
+  echo output will go into file $filn_out
+
+  # cut off hours
+  set ymd = `echo $dtg | cut -c 1-8`
+
+  # decrement string used for input filename by a day if 
+  # interval center is 00 h 
+  # NOTE: whether you need to do this or not depends on how
+  # the rollover of days is managed, also how files are named
+  # (0Z vs 24Z).
+  set hh = `echo $dtg | cut -c 9-10`
+  if ( $hh == "00" ) then
+    set ymd = `echo $dtg -24h | $advance_exec | cut -c 1-8`
+  endif
+    
+  # FIXME:
+  #  for input 'filename_seq' file, this could be a list of 
+  #  files if the output file you want spans multiple inputs.
+  #  the specific name also depends on what time range the inputs
+  #  cover -- 0Z to 0Z, or 3Z to 3Z, etc.
+
+  # change the values in the template file and overwrite the
+  # old input.nml - this controls what the execution of the
+  # obs_sequence_tool will do.
+  sed -e "s/^.*first_obs_days *=.*/first_obs_days\ =\ $start_day\,/g" \
+      -e "s/^.*first_obs_seconds *=.*/first_obs_seconds\ =\ $start_sec\,/g" \
+      -e "s/^.*last_obs_days *=.*/last_obs_days\ =\ $end_day\,/g" \
+      -e "s/^.*last_obs_seconds *=.*/last_obs_seconds\ =\ $end_sec\,/g" \
+      -e "s/^.*filename_seq *=.*/filename_seq=\'obs_seq${ymd}\'\,/g" \
+      -e "s/^.*filename_out *=.*/filename_out=\'obs_seq${dtg}.bin\'\,/g" \
+      $nml_template > input.nml      
+
+  # do the splitting here
+  ./obs_sequence_tool
+
+  # copy or move the temporary file to the output location
+  ${MOVE} obs_seq${dtg}.bin $filn_out