Changeset 755

Timestamp:

Sep 8, 2012 10:14:53 AM (11 years ago)

Author:

vondreele

Message:

fix rotation about view direction
eliminate divide by zero error in quaternion stuff

Location:

trunk

Files:

• GSASIImath.py (modified) (2 diffs)
• GSASIIphsGUI.py (modified) (2 diffs)
• GSASIIplot.py (modified) (2 diffs)

trunk/GSASIImath.py

@@ -1065 +1065 @@
     Q = np.zeros(4)
     d = np.sqrt(np.sum(np.array(V)**2))
-    V /= d
+    if d:
+        V /= d
+    else:
+        return [1.,0.,0.,0.]    #identity
     p = A/2.
     Q[0] = np.cos(p)
@@ -1078 +1081 @@
     Q = np.zeros(4)
     d = np.sqrt(np.sum(np.array(V)**2))
-    V /= d
+    if d:
+        V /= d
+    else:
+        return [1.,0.,0.,0.]    #identity
     p = A/2.
     Q[0] = cosd(p)

trunk/GSASIIphsGUI.py

@@ -1564 +1564 @@
             'vdwScale':0.67,'ellipseProb':50,'sizeH':0.50,'unitCellBox':False,
             'showABC':True,'selectedAtoms':[],'Atoms':[],'oldxy':[],
-            'Quaternion':[0.0,0.0,1.0,0.0],'bondList':{},'viewDir':[0,0,1]}
+            'Quaternion':[1.0,0.0,0.0,0.0],'bondList':{},'viewDir':[0,0,1]}
         try:
             drawingData = data['Drawing']
@@ -1577 +1577 @@
             drawingData['viewDir'] = [0,0,1]
         if 'Quaternion' not in drawingData:
-            drawingData['Quaternion'] = [0.0,0.0,1.0,0.0]
+            drawingData['Quaternion'] = [1.0,0.0,0.0,0.0]
         cx,ct,cs,ci = [0,0,0,0]
         if generalData['Type'] == 'nuclear':

trunk/GSASIIplot.py

@@ -2672 +2672 @@
 #first get rotation vector (= view vector) in screen coords. & angle increment        
         View = glGetIntegerv(GL_VIEWPORT)
+        cent = [View[2]/2,View[3]/2]
         oldxy = drawingData['oldxy']
         if not len(oldxy): oldxy = list(newxy)
@@ -2677 +2678 @@
         drawingData['oldxy'] = list(newxy)
         V = drawingData['viewDir']
-        X0 = drawingData['viewPoint'][0]
-        A = (dxy[0]+dxy[1])*.25
-# next transform vector back to xtal coordinates via inverse quaternion
-# & make new quaternion
+        A = [0,0]
+        A[0] = dxy[1]*.25
+        A[1] = dxy[0]*.25
+        if newxy[0] > cent[0]:
+            A[0] *= -1
+        if newxy[1] < cent[1]:
+            A[1] *= -1        
+# next transform vector back to xtal coordinates & make new quaternion
         Q = drawingData['Quaternion']
         V = np.inner(Amat,V)
-        DQ = G2mth.AVdeg2Q(A,V)
-        Q = G2mth.prodQQ(Q,DQ)
+        Qx = G2mth.AVdeg2Q(A[0],V)
+        Qy = G2mth.AVdeg2Q(A[1],V)
+        Q = G2mth.prodQQ(Q,Qx)
+        Q = G2mth.prodQQ(Q,Qy)
         drawingData['Quaternion'] = Q