add spherical harmonics to scriptable; add test of pytexture to test_scriptref; minor cleanup of GUI code for SH

Author: briantoby

GSASII/GSASIIddataGUI.py

@@ -207,13 +207,21 @@ def OnPOAxis(event):
         Obj.SetValue('%3d %3d %3d'%(h,k,l))
 
     def OnPOOrder(event):
+        '''Respond when the SH order is changed in the GUI.
+        Updates the dict with the cylindrical Spherical harmonics 
+        coefficients for the specified order, retaining values from 
+        the previous dict, if values were already present
+        '''
         Obj = event.GetEventObject()
         Order = int(Obj.GetValue())
         UseList[G2frame.hist]['Pref.Ori.'][4] = Order
-        UseList[G2frame.hist]['Pref.Ori.'][5] = SetPOCoef(Order,G2frame.hist)
+        UseList[G2frame.hist]['Pref.Ori.'][5] = SetPOCoef(Order)
         wx.CallLater(100,RepaintHistogramInfo,DData.GetScrollPos(wx.VERTICAL))
 
     def OnPOType(event):
+        '''Respond when the SH type is changed in the GUI.
+        Note that values set that are not used are also not changed.
+        '''
         Obj = event.GetEventObject()
         if 'March' in Obj.GetValue():
             UseList[G2frame.hist]['Pref.Ori.'][0] = 'MD'
@@ -251,12 +259,16 @@ def OnAddFixed(event):
         UseList[G2frame.hist]['FixedSeqVars'] = [phaseKeys[i] for i in sel]
         wx.CallLater(100,RepaintHistogramInfo,DData.GetScrollPos(wx.VERTICAL))
 
-    def SetPOCoef(Order,hist):
+    def SetPOCoef(Order):
+        '''Sets up a dict with the cylindrical Spherical harmonics 
+        coefficients for the specified order. 
+        Retains values from the previous dict, if values were already present
+        '''
         cofNames = G2lat.GenSHCoeff(SGData['SGLaue'],'0',Order,False)     #cylindrical & no M
-        newPOCoef = dict(zip(cofNames,np.zeros(len(cofNames))))
+        newPOCoef = dict(zip(cofNames,len(cofNames)*[0.]))
         POCoeff = UseList[G2frame.hist]['Pref.Ori.'][5]
         for cofName in POCoeff:
-            if cofName in  cofNames:
+            if cofName in cofNames:
                 newPOCoef[cofName] = POCoeff[cofName]
         return newPOCoef
 

GSASII/GSASIIscriptable.py

@@ -4998,21 +4998,25 @@ def HAPvalue(self, param=None, newValue=None, targethistlist='all'):
         """Retrieves or sets individual HAP parameters for one histogram or
         multiple histograms.
 
-
         :param str param: is a parameter name, which can be 'Scale' or
           'PhaseFraction' (either can be used for phase
-          fraction), 'Use', 'Extinction' or 'LeBail'.
+          fraction), 'Use', 'Extinction', 'LeBail', 'PO' 
+          (for Prefered Orientation).
           If not specified or invalid
           an exception is generated showing the list of valid parameters.
           At present, these HAP parameters cannot be access with this function:
-          'Pref.Ori.', 'Size', 'Mustrain', 'HStrain', 'Babinet'. On request this
+          'Size', 'Mustrain', 'HStrain', 'Babinet'. On request this
           might be addressed in the future. Some of these values can be set via
           :meth:`G2Phase.set_HAP_refinements`.
         :param newValue: the value to use when setting the HAP parameter for the
           appropriate histogram(s). Will be converted to the proper type or
           an exception will be generated if not possible. If not specified,
           and only one histogram is selected, the value is retrieved and
           returned.
+          When param='PO' then this value is interpreted as the following:
+            if the value is 0 or an even integer, then the preferred 
+            orientation model is set to "Spherical harmonics". If the value is 
+            1, then "March-Dollase" is used. Any other value generates an error.
         :param list targethistlist: a list of histograms where each item in the
             list can be a histogram object (:class:`G2PwdrData`),
             a histogram name or the index number of the histogram.
@@ -5022,7 +5026,8 @@ def HAPvalue(self, param=None, newValue=None, targethistlist='all'):
             are used.
 
             targethistlist must correspond to a single histogram if a value
-            is to be returned (when argument newValue is not specified).
+            is to be returned (i.e. when argument newValue is not specified).
+        :param int order: is a value for the order when     
 
         :returns: the value of the parameter, when argument newValue is not specified.
 
@@ -5050,17 +5055,20 @@ def HAPvalue(self, param=None, newValue=None, targethistlist='all'):
         refFloatParam = ('Scale','Extinction')
         useBool = False
         useFloat = False
+        useInt = False
         if param == 'PhaseFraction': param = 'Scale'
         if param in boolParam:
             useBool = True
         elif param in refFloatParam:
             useFloat = True
+        elif param in ['PO']:
+            useInt = True
         else:
             s = ''
-            for i in boolParam+refFloatParam+['PhaseFraction']:
+            for i in boolParam+refFloatParam+['PhaseFraction','PO']:
                 if s != '': s += ', '
                 s += f'"{i}"'
-            raise G2ScriptException('Invalid parameter. Valid choices are: '+s)
+            raise G2ScriptException(f'Invalid parameter. Valid choices are: {s}')
         if not doSet and len(targethistlist) > 1:
             raise G2ScriptException(f'Unable to report value from {len(targethistlist)} histograms')
         for h in targethistlist:
@@ -5076,6 +5084,28 @@ def HAPvalue(self, param=None, newValue=None, targethistlist='all'):
                 self.data['Histograms'][h][param] = bool(newValue)
             elif useFloat:
                 self.data['Histograms'][h][param][0] = float(newValue)
+            elif useInt:
+                if newValue is None:
+                    return self.data['Histograms'][h]['Pref.Ori.']
+                try:
+                    intval = int(newValue)
+                except:
+                    intval = None
+                if intval == 1:
+                    self.data['Histograms'][h]['Pref.Ori.'][0] = 'MD'
+                elif intval is not None and 2*int(intval//2) == intval:
+                    SGData = self.data['General']['SGData']
+                    cofNames = G2lat.GenSHCoeff(SGData['SGLaue'],'0',intval,False)     #cylindrical & no M
+
+                    self.data['Histograms'][h]['Pref.Ori.'][0] = 'SH'
+                    self.data['Histograms'][h]['Pref.Ori.'][4] = intval
+                    olddict = self.data['Histograms'][h]['Pref.Ori.'][5]
+                    newdict = dict(zip(cofNames,len(cofNames)*[0.]))
+                    # retain any old values in existing dict
+                    newdict.update({i:olddict[i] for i in olddict if i in newdict})
+                    self.data['Histograms'][h]['Pref.Ori.'][5] = newdict
+                else:
+                    raise G2ScriptException(f'Preferred orientation value of {newValue} is invalid')
             else:
                 print('unexpected action')
 

tests/test_scriptref.py

@@ -73,6 +73,16 @@ def testR(msg,w1,w2):
     h2.set_refinements({'Instrument Parameters': ['U', 'V', 'W']})
     gpx.refine()
     testR('add UVW',10.785432,  4.130126)
+    # change to Spherical Harmonics, order=2 for the 1st histogram & refine
+    phase0.HAPvalue('PO',2,[h1])
+    phase0.set_HAP_refinements({"Pref.Ori.":True})
+    gpx.refine()
+    POdict = phase0.HAPvalue('PO',targethistlist=[h1])[5]
+    print('Spherical harmonics values:',POdict)
+    npt.assert_allclose((POdict['C(2,0)'],POdict['C(2,2)']),
+                            [0.1171084051086,0.11462063648716], rtol=0.001)
+    testR('add PO',10.496639, 4.128754)
+    #
     print('OK')
 
 if __name__ == '__main__':