Re #9579. Usage example for MaskDetectorsinShape.

Code/Mantid/Framework/DataHandling/src/MaskDetectorsInShape.cpp

@@ -31,7 +31,7 @@ void MaskDetectorsInShape::init()
   declareProperty(new WorkspaceProperty<> ("Workspace", "", Direction::InOut),
       "The input workspace");
   declareProperty("ShapeXML", "", boost::make_shared<MandatoryValidator<std::string> >(),
-      "The XML definition of the user defined shape.  [[HowToDefineGeometricShape]] provides a description of the syntax.");
+      "The XML definition of the user defined shape.");
   declareProperty("IncludeMonitors", false,
       "Whether to include monitors if they are contained in the shape (default false)");
 }

Code/Mantid/docs/source/algorithms/MaskDetectorsInShape-v1.rst

@@ -17,6 +17,9 @@ instrument and masks any detector detectors that in contained within it.
 A detector is considered to be contained it its central location point
 is contained within the shape.
 
+`This page <http://www.mantidproject.org/HowToDefineGeometricShape>`_
+provides a description of the syntax of ShapeXML string.
+
 ChildAlgorithms used
 ####################
 
@@ -26,4 +29,56 @@ MaskDetectorsInShape runs the following algorithms as child algorithms:
    detectors that are contained in the user defined shape.
 -  :ref:`algm-MaskDetectors` - To mask the detectors found.
 
+
+Usage
+-----
+
+.. testcode::
+
+  # Create a workspace
+  ws = CreateSampleWorkspace()
+
+  # Define an infinite cylinder with its axis parallel to the Z-axis
+  # and the radius of 0.04
+  shapeXML = \
+  """
+  <infinite-cylinder id="A" >
+      <centre x="0" y="0" z="0" />
+      <axis x="0" y="0" z="1" />
+      <radius val="0.04" />
+  </infinite-cylinder>
+  """
+  # Mask all detectors inside this cylinder
+  MaskDetectorsInShape( ws, shapeXML )
+
+  #Check the result
+  masked_dets =  []
+  inside_dets = []
+  # Collect separately all masked detector IDs and IDs of detectors
+  # that are inside the cylinder defined by shapeXML
+  R2 = 0.04**2 # cylinder radius sqared
+  for i in range(ws.getNumberHistograms()):
+    det = ws.getDetector(i)
+    if det.isMasked():
+      masked_dets.append( det.getID() )
+    r = det.getPos()
+    if r.X()**2 + r.Y()**2 <= R2:
+      inside_dets.append( det.getID() )
+
+  # Print out the IDs
+  print masked_dets
+  print inside_dets
+
+  # Check that the two arrays are equal
+  print masked_dets == inside_dets
+
+Output
+######
+
+.. testoutput::
+
+  [100, 101, 102, 103, 104, 105, 110, 111, 112, 113, 114, 120, 121, 122, 123, 124, 130, 131, 132, 133, 134, 140, 141, 142, 143, 150, 200, 201, 202, 203, 204, 205, 210, 211, 212, 213, 214, 220, 221, 222, 223, 224, 230, 231, 232, 233, 234, 240, 241, 242, 243, 250]
+  [100, 101, 102, 103, 104, 105, 110, 111, 112, 113, 114, 120, 121, 122, 123, 124, 130, 131, 132, 133, 134, 140, 141, 142, 143, 150, 200, 201, 202, 203, 204, 205, 210, 211, 212, 213, 214, 220, 221, 222, 223, 224, 230, 231, 232, 233, 234, 240, 241, 242, 243, 250]
+  True
+
 .. categories::