[GRASS-SVN] r39312 - in grass-addons/raster: . r.burn.frict

[svn_grass at osgeo.org]

Author: benducke
Date: 2009-09-28 10:01:21 -0400 (Mon, 28 Sep 2009)
New Revision: 39312

Added:
   grass-addons/raster/r.burn.frict/
   grass-addons/raster/r.burn.frict/Makefile
   grass-addons/raster/r.burn.frict/description.html
   grass-addons/raster/r.burn.frict/r.burn.frict
Log:
Added r.burn.frict

Added: grass-addons/raster/r.burn.frict/Makefile
===================================================================
--- grass-addons/raster/r.burn.frict/Makefile	                        (rev 0)
+++ grass-addons/raster/r.burn.frict/Makefile	2009-09-28 14:01:21 UTC (rev 39312)
@@ -0,0 +1,8 @@
+MODULE_TOPDIR = ../..
+
+PGM = r.burn.frict
+
+include $(MODULE_TOPDIR)/include/Make/Script.make
+
+default: script
+

Added: grass-addons/raster/r.burn.frict/description.html
===================================================================
--- grass-addons/raster/r.burn.frict/description.html	                        (rev 0)
+++ grass-addons/raster/r.burn.frict/description.html	2009-09-28 14:01:21 UTC (rev 39312)
@@ -0,0 +1,21 @@
+<h2>DESCRIPTION</h2>
+
+<em>r.burn.frict</em>
+<p>
+Converts vector geometries to raster cells, using a simple anti-aliasing method to close "gaps" between diagonal cells.
+Useful for "burning" vector geometries into a friction surface, making sure that simulated movement does not "slip" through converted cells that have only diagonal neighbours.
+
+<h2>BACKGROUND</h2>
+
+In movement analysis using cost surfaces and shortest path algorithms, it may be desirable to add vectorial features to the friction surface to simulate bounded
+features that impact movement, such as pathways or barriers. 
+If those features are represented by vector lines (e.g. road networks), then it must be ensured that the conversion to raster cells will not leave "gaps" between
+diagonal cells as this would allow simulated movement to "slip" through them.
+This module performs simple gap closing in a 2x2 cell window. It replaces gaps with the average of two neighbouring cells (on one side only), which results in the same friction for crossing cells, no matter in which direction.
+
+<h2>AUTHOR</h2>
+Benjamin Ducke, benjamin.ducke AT oadigital.net
+<p>
+<i>Last changed: Mon Sep 28 2009</i>
+</p>
+

Added: grass-addons/raster/r.burn.frict/r.burn.frict
===================================================================
--- grass-addons/raster/r.burn.frict/r.burn.frict	                        (rev 0)
+++ grass-addons/raster/r.burn.frict/r.burn.frict	2009-09-28 14:01:21 UTC (rev 39312)
@@ -0,0 +1,126 @@
+#!/bin/sh
+
+############################################################################
+#
+# MODULE:       r.burn.frict
+# AUTHOR(S):    Benjamin Ducke <benjamin.ducke AT oadigital.net>
+# PURPOSE:      Converts vector geometries to raster cells, using a simple
+#		anti-aliasing methods to close "gaps" between diagonal cells.
+#		Useful for "burning" vector geometries into a friction surface,
+#               making sure that simulated movement does not "slip" through
+#               converted cells that have only diagonal neighbours.
+#
+# COPYRIGHT:    (C) 2009 by Benjamin Ducke
+#
+#               This program is free software under the GNU General Public
+#               License (>=v2). Read the file COPYING that comes with GRASS
+#               for details.
+#
+#############################################################################
+
+#%Module
+#% description: "Burns" vector features into a raster map, closing diagonal gaps between burned cells.
+#% keywords: vector, raster, friction
+#%End
+
+#%Option
+#% key: features
+#% type: string
+#% required: yes
+#% multiple: no
+#% key_desc: name
+#% description: Name of input vector map (features)
+#% gisprompt: old,vector,vector
+#%End
+
+#%Option
+#% key: surface
+#% type: string
+#% required: no
+#% multiple: no
+#% key_desc: name
+#% description: Name of input raster map (friction surface)
+#% gisprompt: old,cell,raster
+#%End
+
+#%Option
+#% key: output
+#% type: string
+#% required: yes
+#% multiple: no
+#% key_desc: name
+#% description: Name of output raster map
+#% gisprompt: new,cell,raster
+#%End
+
+#%Option
+#% key: const
+#% type: double
+#% required: no
+#% multiple: no
+#% description: Constant value to burn into friction surface.
+#%End
+
+#%Option
+#% key: column
+#% type: string
+#% required: no
+#% multiple: no
+#% key_desc: name
+#% description: Name of column with value to burn into friction surface
+#% gisprompt: old_dbcolumn,dbcolumn,dbcolumn
+#%End
+
+
+if [ -z "$GISBASE" ] ; then
+    echo "ERROR: You must be in GRASS GIS to run this program." 1>&2
+    exit 1
+fi
+
+if [ "$1" != "@ARGS_PARSED@" ] ; then
+    exec g.parser "$0" "$@"
+fi
+
+if [ -z "$GIS_OPT_CONST" ] && [ -z "$GIS_OPT_COLUMN" ] ; then
+    echo "ERROR: Please specify either a constant value or a column name" 1>&2
+    exit 1
+fi
+
+if [ -n "$GIS_OPT_CONST" ] && [ -n "$GIS_OPT_COLUMN" ] ; then
+    echo "ERROR: Please specify either a constant value or a column name" 1>&2
+    exit 1
+fi
+
+
+# burn vectors into output map: CONST value
+if [ -n "$GIS_OPT_CONST" ] ; then
+    CMD="use=val value=${GIS_OPT_CONST}"
+fi
+
+# burn vectors into output map: COLUMN value
+if [ -n "$GIS_OPT_COLUMN" ] ; then
+    CMD="use=attr column=${GIS_OPT_COLUMN}"
+fi
+
+# do it!
+v.to.rast input=$GIS_OPT_FEATURES output=$GIS_OPT_OUTPUT $CMD
+
+# Perform simple gap closing in a 2x2 window: replace gap with average
+# of two neighbouring cells (on one side only).
+# This results in the same friction for crossing cells, no matter in
+# which direction.
+MAP=$GIS_OPT_OUTPUT
+r.mapcalc "$MAP=if(isnull($MAP) && !isnull($MAP[-1,0]) && isnull($MAP[-1,1])  && !isnull($MAP[0,1]) ,($MAP[-1,0]+$MAP[0,1] )/2.0,$MAP)"
+r.mapcalc "$MAP=if(isnull($MAP) && !isnull($MAP[0,-1]) && isnull($MAP[-1,-1]) && !isnull($MAP[-1,0]),($MAP[0,-1]+$MAP[-1,0])/2.0,$MAP)"
+
+# if no surface is given, replace all NULL cells in the output map with "1.0" ...
+if [ -z "$GIS_OPT_SURFACE" ] ; then
+    r.mapcalc "$MAP=if(isnull($MAP),1.0,$MAP)"
+fi
+
+# ... otherwise with the cell values in the friction map.
+if [ -n "$GIS_OPT_SURFACE" ] ; then
+    r.mapcalc "$MAP=if(isnull($MAP),$GIS_OPT_SURFACE,$MAP)"
+fi
+
+exit 0