Changeset 4570

Timestamp:

Sep 16, 2020 9:04:32 PM (3 years ago)

Author:

vondreele

Message:

Implement arc mask method for determining polarization with scipy minimize_scalar method to find minimum difference between arc mask on/mask off integrations

Location:

trunk

Files:

• GSASIIimage.py (modified) (1 diff)
• GSASIIimgGUI.py (modified) (2 diffs)
• GSASIIphsGUI.py (modified) (1 diff)

trunk/GSASIIimage.py

@@ -1507 +1507 @@
                 break
     return mask
+
+def DoPolaCalib(ImageZ,imageData,arcTth):
+    ''' Determine image polarization by successive integrations with & without preset arc mask.
+    '''
+    from scipy.optimize import minimize_scalar
+    Arc = [arcTth,[45.,135.],2.0]
+    Masks = {'Points':[],'Rings':[],'Arcs':[],'Polygons':[],'Frames':[],
+        'Thresholds':imageData['range'],'SpotMask':{'esdMul':3.,'spotMask':None}}
+    AMasks = {'Points':[],'Rings':[],'Arcs':[Arc,],'Polygons':[],'Frames':[],
+        'Thresholds':imageData['range'],'SpotMask':{'esdMul':3.,'spotMask':None}}
+    data = copy.deepcopy(imageData)
+    
+    def func(p):
+        p = min(1.0,max(p,0.0))
+        data['PolaVal'][0] = p
+        H0 = ImageIntegrate(ImageZ,data,Masks)[0]
+        H0A = ImageIntegrate(ImageZ,data,AMasks)[0]
+        M = np.sum(H0-H0A)
+        print('polarization %.4f, fxn: %.1f'%(p,M))
+        return M**2
+    
+    res = minimize_scalar(func,bracket=[1.,.999],tol=.0001)
+    print(res)
+    pola = min(1.0,max(res.x,.0))
+    imageData['PolaVal'][0] = pola

trunk/GSASIIimgGUI.py

@@ -136 +136 @@
         G2plt.PlotExposedImage(G2frame,newPlot=True,event=tc.event)
         
-    #G2frame.dataWindow.ClearData()
+    def OnPolaCalib(event):
+        IOtth = [data['IOtth'][0]+2.,data['IOtth'][1]-2.]
+        dlg = G2G.SingleFloatDialog(G2frame,'Polarization test arc mask',
+''' Do not use if pattern has uneven absorption
+ Set 2-theta max in image controls to be fully inside image  
+ Enter 2-theta position for arc mask (%.1f-%.1f) '''%(IOtth[0],IOtth[1]),IOtth[1],IOtth,format='%.2f')
+        if dlg.ShowModal() == wx.ID_OK:
+            arcTth = dlg.GetValue()
+            G2fil.G2SetPrintLevel('none')
+            G2img.DoPolaCalib(G2frame.ImageZ,data,arcTth)
+            G2fil.G2SetPrintLevel('all')
+            UpdateImageData(G2frame,data)
+        dlg.Destroy()
+        
+    G2frame.dataWindow.ClearData()
     G2frame.ImageZ = GetImageZ(G2frame,data)
     mainSizer = G2frame.dataWindow.GetSizer()
@@ -161 +175 @@
     distSizer.Add(G2G.ValidatedTxtCtrl(G2frame.dataWindow,data['PolaVal'],0,nDig=(10,4),
         xmin=0.,xmax=1.,typeHint=float),0,WACV)
+    polaCalib = wx.Button(G2frame.dataWindow,label='Calibrate?')
+    polaCalib.Bind(wx.EVT_BUTTON,OnPolaCalib)
+    distSizer.Add(polaCalib,0,WACV)
     mainSizer.Add(distSizer,0)
     if 'samplechangerpos' not in data or data['samplechangerpos'] is None:
         data['samplechangerpos'] = 0.0
     mainSizer.Add(wx.StaticText(G2frame.dataWindow,label='Sample changer position %.2f mm'%data['samplechangerpos']),0,WACV)
+    G2frame.dataWindow.SetDataSize()
 
 ################################################################################

trunk/GSASIIphsGUI.py

@@ -11728 +11728 @@
         const = 9.e-2/(np.pi*Sample['Gonio. radius'])                  #shifts in microns
         gconst = 2.35482 # sqrt(8 ln 2)
+        dx = (xdata[0][1]-xdata[0][0])*20.              #this ian approximation - not correct, but CW seems to be needed
+        gconst *= dx
         
         wx.BeginBusyCursor()