Refs #9570 Added SPE format

The SPE page now has details on its format

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

@@ -12,15 +12,113 @@ Description
 Saves the data in a workspace into a file in the ASCII 'SPE' format (as
 described `here <Media:Spe_file_format.pdf>`__).
 
-The units used for saving will match those of the input workspace, such
-that if you have the units Momentum Transfer ('DeltaE') then you will
-get a traditional SPE file, you could choose to have the units in mod Q
-and then it will save to an SPQ file variant.
+The units used for saving will match those of the input workspace, such that if you have the units Momentum Transfer ('DeltaE') then you will get a traditional SPE file, you could choose to have the units in mod Q and then it will save to an SPQ file variant.
+
+Format of .SPE files
+####################
+
+::
+
+    ndet ne ! number of workspaces and number of energy bins
+    ### Phi Grid ! angular boundaries i.e. (ndet+1) values
+    ang(0) ang(1) … ang(7)
+    ang(8) ang(9) … ang(15)
+    :
+    :
+    … ang(ndet)
+    ### Energy Grid ! Energy bin boundaries i.e. (ne+1) values
+    en(0) en(1) … en(7)
+    en(8) en(9) … en(15)
+    :
+    :
+    … en(ne)
+    ### S(Phi,w) ! Intensities for first workspace
+    s(0) s(1) … s(7)
+    s(8) s(9) … s(15)
+    :
+    :
+    … s(ndet-1)
+    ### Errors ! Standard deviation for first workspace
+    err(0) err(1) … err(7)
+    err(8) err(9) … err(15)
+    :
+    :
+    … err(ndet-1)
+    ### S(Phi,w) ! Intensities for second workspace
+    :
+    :
+    ### Errors ! Standard deviation for second workspace
+    :
+    :
+    … and so on until completed ndet workspaces
+
+
+IMPORTANT NOTE: in the array corresponding to the signal, the number |-1030| is to be interpreted as
+not-a-number. That is, the corresponding pixel is to be masked. Usually of course, a detector is
+masked, so that all the signal array corresponding to that workspace will contain |-1030|. The
+corresponding error should be zero.
+
+.. |-1030| replace:: -10\ :sup:`30`
+
+Example file produced by script below
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+::
+
+           1       9
+    ### Phi Grid
+     5.000E-01 1.500E+00
+    ### Energy Grid
+     0.000E+00 1.000E+00 2.000E+00 3.000E+00 4.000E+00 5.000E+00 6.000E+00 7.000E+00
+     8.000E+00 9.000E+00
+    ### S(Phi,w)
+    -1.000E+30-1.000E+30-1.000E+30-1.000E+30-1.000E+30-1.000E+30-1.000E+30-1.000E+30
+    -1.000E+30
+    ### Errors
+     0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00
+     0.000E+00
+
 
 Restrictions on the input workspace
 ###################################
 
 The input workspace must contain histogram data with common binning on
 all spectra.
 
-.. categories::
+Usage
+-----
+
+**Example - Save a workspace in SPE format**
+
+.. testcode:: ExSPESimple
+
+    #import the os path libraries for directory functions
+    import os
+
+    # create histogram workspace
+    dataX1 = [0,1,2,3,4,5,6,7,8,9] # or use dataX1=range(0,10)
+    dataY1 = [0,1,2,3,4,5,6,7,8] # or use dataY1=range(0,9)
+    dataE1 = [1,1,1,1,1,1,1,1,1] # or use dataE1=[1]*9
+
+    ws1 = CreateWorkspace(dataX1, dataY1, dataE1)
+
+    #Create an absolute path by joining the proposed filename to a directory
+    #os.path.expanduser("~") used in this case returns the home directory of the current user
+    savefile = os.path.join(os.path.expanduser("~"), "SPEFile.spe")
+
+    # perform the algorithm
+    SaveSPE(InputWorkspace=ws1,Filename=savefile)
+
+    print "File Exists:", os.path.exists(savefile)
+
+.. testcleanup:: ExSPESimple
+
+    os.remove(savefile)
+
+Output:
+
+.. testoutput:: ExSPESimple
+
+    File Exists: True
+
+.. categories::