[GRASS-SVN] r29828 - grass/trunk/scripts/r.regression.line

[svn_grass at osgeo.org]

Author: neteler
Date: 2008-01-25 05:33:02 -0500 (Fri, 25 Jan 2008)
New Revision: 29828

Modified:
   grass/trunk/scripts/r.regression.line/r.regression.line
Log:
don't fail on empty map(s)

Modified: grass/trunk/scripts/r.regression.line/r.regression.line
===================================================================
--- grass/trunk/scripts/r.regression.line/r.regression.line	2008-01-25 10:32:16 UTC (rev 29827)
+++ grass/trunk/scripts/r.regression.line/r.regression.line	2008-01-25 10:33:02 UTC (rev 29828)
@@ -91,6 +91,11 @@
 
 #calculate regression equation
 r.stats -cnA input=$GIS_OPT_MAP1,$GIS_OPT_MAP2  > "$TMP"
+if [ ! -s "$TMP" ] ; then
+    g.message -e "One or both input maps only contain no data (NULL) pixels in the current region"
+    exit 1
+fi
+
 awk '{tot += $3;sumX +=$1 * $3; sumsqX +=$1*$1*$3;sumY +=$2 * $3; sumsqY +=$2*$2*$3;\
  sumXY +=$1*$2*$3;\
 }\