From aa039cb83c1f588b747da3d142651ea9fdbf926f Mon Sep 17 00:00:00 2001
From: cfarmer <cfarmer@c8812cc2-4d05-0410-92ff-de0c093fc19c>
Date: Mon, 25 May 2009 21:05:34 +0000
Subject: [PATCH] fix basic statistics calculation ( mean no longer always
 0.00! )

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@10848 c8812cc2-4d05-0410-92ff-de0c093fc19c
---
 python/plugins/fTools/tools/doVisual.py | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/python/plugins/fTools/tools/doVisual.py b/python/plugins/fTools/tools/doVisual.py
index e8e21008e4d6..7fb6957bd28d 100755
--- a/python/plugins/fTools/tools/doVisual.py
+++ b/python/plugins/fTools/tools/doVisual.py
@@ -174,11 +174,11 @@ def basic_statistics( self, vlayer, myField ):
     fields = vprovider.fields()
     index = vprovider.fieldNameIndex( myField )
     feat = QgsFeature()
-    sumVal = 0
-    meanVal = 0
-    stdVal = 0
-    cvVal = 0
-    nVal = 0
+    sumVal = 0.0
+    meanVal = 0.0
+    stdVal = 0.0
+    cvVal = 0.0
+    nVal = 0.0
     values = []
     first = True
     nFeat = vprovider.featureCount()
@@ -196,20 +196,17 @@ def basic_statistics( self, vlayer, myField ):
         if value < minVal: minVal = value
         if value > maxVal: maxVal = value
       values.append( value )
-      sumVal = sumVal + value
+      sumVal = float( sumVal + value )
       nElement += 1
       self.emit( SIGNAL( "runStatus(PyQt_PyObject)" ), nElement )
     nVal= float( len( values ) )
-    print "to here"
-    if not nVal > 0.00:
-      print "then here"
+    if nVal > 0.00:
       meanVal = float( sumVal ) / nVal
       if not meanVal == 0.00:
         for val in values:
-          stdVal += ( ( val - meanVal ) * ( val - meanVal ) )
-        print "finally here"
-        stdVal = math.sqrt( stdVal / nVal )
-        cvVal = stdVal / meanVal
+          stdVal += float( ( val - meanVal ) * ( val - meanVal ) )
+        stdVal = float( math.sqrt( stdVal / nVal ) )
+        cvVal = float( stdVal / meanVal )
     lstStats = []
     lstStats.append( "Mean    : " + unicode( meanVal ) )
     lstStats.append( "StdDev : " + unicode( stdVal ) )