Merge remote-tracking branch 'origin/feature/8455_correct_sample_geom…

…_cor'

Code/Mantid/scripts/reduction/instruments/sans/sans_reduction_steps.py

@@ -750,35 +750,45 @@ class SampleGeomCor(ReductionStep):
         ORNL only divides by thickness, in the absolute scaling step
 
     """
-    def execute(self, reducer, workspace):
-        """
-            Divide the counts by the volume of the sample
-        """
-        self.geo = reducer._sample_run.geometry
-        assert( issubclass(self.geo.__class__, GetSampleGeom))
+    def __init__(self):
+        self.volume = 1.0
+
+    def calculate_volume(self, reducer):
+        geo = reducer.get_sample().geometry
+        assert( issubclass(geo.__class__, GetSampleGeom))
 
         try:
-            if self.geo.shape == 'cylinder-axis-up':
+            if geo.shape == 'cylinder-axis-up':
                 # Volume = circle area * height
                 # Factor of four comes from radius = width/2
-                volume = self.geo.height*math.pi
-                volume *= math.pow(self.geo.width,2)/4.0
-            elif self.geo.shape == 'cuboid':
+                volume = geo.height*math.pi
+                volume *= math.pow(geo.width,2)/4.0
+            elif geo.shape == 'cuboid':
                 # Flat plate sample
-                volume = self.geo.width
-                volume *= self.geo.height*self.geo.thickness
-            elif self.geo.shape == 'cylinder-axis-along':
+                volume = geo.width
+                volume *= geo.height*geo.thickness
+            elif geo.shape == 'cylinder-axis-along':
                 # Factor of four comes from radius = width/2
                 # Disc - where height is not used
-                volume = self.geo.thickness*math.pi
-                volume *= math.pow(self.geo.width, 2)/4.0
+                volume = geo.thickness*math.pi
+                volume *= math.pow(geo.width, 2)/4.0
             else:
-                raise NotImplemented('Shape "'+self.geo.shape+'" is not in the list of supported shapes')
+                raise NotImplemented('Shape "'+geo.shape+'" is not in the list of supported shapes')
         except TypeError:
-            raise TypeError('Error calculating sample volume with width='+str(self._width) + ' height='+str(self._height) + 'and thickness='+str(self._thickness)) 
-
-        ws = mtd[workspace]
-        ws /= volume
+            raise TypeError('Error calculating sample volume with width='+str(geo.width) + ' height='+str(geo.height) + 'and thickness='+str(geo.thickness)) 
+
+        return volume
+
+    def execute(self, reducer, workspace):
+        """
+            Divide the counts by the volume of the sample
+        """
+        if not reducer.is_can():
+            # it calculates the volume for the sample and may or not apply to the can as well.
+            self.volume = self.calculate_volume(reducer)
+
+        ws = mtd[str(workspace)]
+        ws /= self.volume
 
 class StripEndZeros(ReductionStep):
     # ISIS only