Changeset 3888 for trunk/GSASIImath.py

Timestamp:

Apr 11, 2019 3:59:48 PM (4 years ago)

Author:

vondreele

Message:

provide contour plot (not finished yet) on structure drawing

File:

• trunk/GSASIImath.py (modified) (1 diff)

trunk/GSASIImath.py

@@ -3650 +3650 @@
     return R
        
+def getRhos(XYZ,rho):
+    ''' get scattering density at a point by 8-point interpolation
+    param xyz:  array coordinates to be probed Nx3
+    param: rho: array copy of map (NB: don't use original!)
+    
+    :returns: density at xyz
+    '''
+    rollMap = lambda rho,roll: np.roll(np.roll(np.roll(rho,roll[0],axis=0),roll[1],axis=1),roll[2],axis=2)
+    mapShape = np.array(rho.shape)
+    mapStep = 1./mapShape
+    X = XYZ%1.    #get into unit cell
+    I = np.array(np.rint(X*mapShape),dtype='int')
+    R = []
+    for i,x in enumerate(X):
+        D = x-I[i]*mapStep         #position inside map cell
+        D12 = D[0]*D[1]
+        D13 = D[0]*D[2]
+        D23 = D[1]*D[2]
+        D123 = np.prod(D)
+        Rho = rollMap(rho,-I[i])    #shifts map so point is in corner
+        R.append(Rho[0,0,0]*(1.-np.sum(D))+Rho[1,0,0]*D[0]+Rho[0,1,0]*D[1]+Rho[0,0,1]*D[2]+  \
+            Rho[1,1,1]*D123+Rho[0,1,1]*(D23-D123)+Rho[1,0,1]*(D13-D123)+Rho[1,1,0]*(D12-D123)+  \
+            Rho[0,0,0]*(D12+D13+D23-D123)-Rho[0,0,1]*(D13+D23-D123)-    \
+            Rho[0,1,0]*(D23+D12-D123)-Rho[1,0,0]*(D13+D12-D123))
+    return R
+       
 def SearchMap(generalData,drawingData,Neg=False):
     '''Does a search of a density map for peaks meeting the criterion of peak