Add usage examples for ConvertSpectrumAxis2

Refs #9574

Code/Mantid/docs/source/algorithms/ConvertSpectrumAxis-v2.rst

@@ -19,4 +19,43 @@ duplicates will not be aggregated. Any spectrum for which a detector is
 not found (i.e. if the instrument definition is incomplete) will not
 appear in the output workspace.
 
+Usage
+-----
+
+**Example: Convert vertical axis to theta**
+
+.. testcode::
+
+   # Creates a workspace with some detectors attached
+   dataws = CreateSampleWorkspace(NumBanks=1,BankPixelWidth=2) # 2x2 detector
+
+   theta = ConvertSpectrumAxis(dataws, Target="Theta")
+
+   vertical_axis = theta.getAxis(1)
+   print "There are %d axis values" % vertical_axis.length()
+   print "Final theta value: %f (degrees)" % vertical_axis.getValue(vertical_axis.length() - 1)
+
+.. testoutput::
+
+   There are 4 axis values
+   Final theta value: 0.129645 (degrees)
+
+**Example: Convert vertical axis to elastic Q for direct geometry**
+
+.. testcode::
+
+   # Creates a workspace with some detectors attached
+   dataws = CreateSampleWorkspace(NumBanks=1,BankPixelWidth=2) # 2x2 detector
+
+   qws = ConvertSpectrumAxis(dataws, Target="ElasticQ", EFixed=15., EMode="Direct")
+
+   vertical_axis = qws.getAxis(1)
+   print "There are %d axis values" % vertical_axis.length()
+   print "Final Q value: %f (A^-1)" % vertical_axis.getValue(vertical_axis.length() - 1)
+
+.. testoutput::
+
+   There are 4 axis values
+   Final Q value: 0.006088 (A^-1)
+
 .. categories::