[GRASS-SVN] r59299 - grass-addons/grass6/raster/r.stack

[svn_grass at osgeo.org]

Author: hamish
Date: 2014-03-23 23:57:18 -0700 (Sun, 23 Mar 2014)
New Revision: 59299

Modified:
   grass-addons/grass6/raster/r.stack/r.stack
Log:
optionally use r.patch.many to speed up processing

Modified: grass-addons/grass6/raster/r.stack/r.stack
===================================================================
--- grass-addons/grass6/raster/r.stack/r.stack	2014-03-24 01:07:29 UTC (rev 59298)
+++ grass-addons/grass6/raster/r.stack/r.stack	2014-03-24 06:57:18 UTC (rev 59299)
@@ -40,7 +40,18 @@
 #% description: Name for output raster map
 #% gisprompt: new,cell,raster
 #%End
+#%Option
+#% key: workers
+#% type: integer
+#% multiple: no
+#% key_desc: value
+#% label: Number of parallel sessions
+#% description: Set to 0 to run serially (default).
+#% options: 0-2048
+#% answer: 0
+#%End
 
+
 if [ -z "$GISBASE" ] ; then
     echo "You must be in GRASS GIS to run this program." 1>&2
     exit 1
@@ -66,6 +77,11 @@
     exit 1
 fi
 
+if [ "$GIS_OPT_WORKERS" -ne 0 ] && [ ! -x "`which r.patch.many`" ] ; then
+    g.message "r.patch.many addon required, please install it first" 
+    exit 1
+fi
+
 # set environment so that awk works properly from all locales
 unset LC_ALL
 LC_NUMERIC=C
@@ -104,6 +120,12 @@
 g.region s="$NEW_SOUTH"
 
 #g.copy maps>1 to temporary maps, and set their bounds
+
+############
+# We make the stack vertical because empty rows are skipped
+# over quickly during processing, while empty columns are not.
+############
+
 g.message "Preparation ..."
 NUM=0
 ORIG_IFS="$IFS"
@@ -130,10 +152,12 @@
 
 g.message "Patching ..."
 
-# todo?: if number of maps,rows is excessive, perhaps it is more efficient to
-#  build up by chunks, then patch the chunks together.
-#  Empty rows are skipped over quickly though. (this is why the stack is vertical)
-r.patch input="$FIRST_MAP,$TEMP_MAPS" output="$GIS_OPT_OUTPUT"
+if [ "$GIS_OPT_WORKERS" -eq 0 ] ; then
+   r.patch input="$FIRST_MAP,$TEMP_MAPS" output="$GIS_OPT_OUTPUT"
+else
+   r.patch.many input="$FIRST_MAP,$TEMP_MAPS" output="$GIS_OPT_OUTPUT" \
+      workers="$GIS_OPT_WORKERS"
+fi
 
 # r.patch uses the color map from the first map, which is unwanted here.
 #r.colors -r "$GIS_OPT_OUTPUT"