Merged Seogi's code into the Tensor Mesh code base.

This is under the DiffOperators class, which can be inherited with BaseMesh to any Mesh Object.

Cell area and other dimension calculations are included in the TensorMesh class.

Wrote unit tests for cell vol, area, and edges.

SimPEG/TensorMesh.py

@@ -1,10 +1,11 @@
 import numpy as np
 from BaseMesh import BaseMesh
 from TensorView import TensorView
-from utils import ndgrid
+from DiffOperators import DiffOperators
+from utils import ndgrid, mkvc
 
 
-class TensorMesh(BaseMesh, TensorView):
+class TensorMesh(BaseMesh, TensorView, DiffOperators):
     """
     TensorMesh is a mesh class that deals with tensor product meshes.
 
@@ -186,6 +187,80 @@ class TensorMesh(BaseMesh, TensorView):
     def getCellNumbering(self):
         pass
 
+    # --------------- Geometries ---------------------
+    def vol():
+        doc = "Construct cell volumes of the 3D model as 1d array."
+
+        def fget(self):
+            if(self._vol is None):
+                vh = [mkvc(x, 2) for x in self.h]
+                # Compute cell volumes
+                if(self.dim == 1):
+                    self._vol = mkvc(vh[0])
+                elif(self.dim == 2):
+                    # Cell sizes in each direction
+                    self._vol = mkvc(vh[0]*vh[1].T)
+                elif(self.dim == 3):
+                    # Cell sizes in each direction
+                    v12 = vh[0]*vh[1].T
+                    self._vol = mkvc(mkvc(v12, 2)*vh[2].T)
+            return self._vol
+        return locals()
+    _vol = None
+    vol = property(**vol())
+
+    def area():
+        doc = "Construct face areas of the 3D model as 1d array."
+
+        def fget(self):
+            if(self._area is None):
+                # Ensure that we are working with column vectors
+                vh = [mkvc(x, 2) for x in self.h]
+                # The number of cell centers in each direction
+                n = [x.size for x in self.h]
+                # Compute areas of cell faces
+                if(self.dim == 1):
+                    self._area = np.ones((n[0]+1, 1))
+                elif(self.dim == 2):
+                    area1 = np.ones((n[0]+1, 1))*vh[1].T
+                    area2 = vh[0]*np.ones((n[1]+1, 1)).T
+                    self._area = np.r_[mkvc(area1), mkvc(area2)]
+                elif(self.dim == 3):
+                    area1 = np.ones((n[0]+1, 1))*mkvc(vh[1]*vh[2].T)
+                    area2 = vh[0]*mkvc(np.ones((n[1]+1, 1))*vh[2].T)
+                    area3 = vh[0]*mkvc(vh[1]*np.ones((n[2]+1, 1)).T)
+                    self._area = np.r_[mkvc(area1), mkvc(area2), mkvc(area3)]
+            return self._area
+        return locals()
+    _area = None
+    area = property(**area())
+
+    def edge():
+        doc = "Construct edge legnths of the 3D model as 1d array."
+
+        def fget(self):
+            if(self._area is None):
+                # Ensure that we are working with column vectors
+                vh = [mkvc(x, 2) for x in self.h]
+                # The number of cell centers in each direction
+                n = [x.size for x in self.h]
+                # Compute edge lengths
+                if(self.dim == 1):
+                    self._edge = mkvc(vh[0])
+                elif(self.dim == 2):
+                    l1 = vh[0]*np.ones((n[1]+1, 1)).T
+                    l2 = np.ones((n[0]+1, 1))*vh[1].T
+                    self._edge = np.r_[mkvc(l1), mkvc(l2)]
+                elif(self.dim == 3):
+                    l1 = vh[0]*mkvc(np.ones((n[1]+1, 1))*np.ones((n[2]+1, 1)).T)
+                    l2 = np.ones((n[0]+1, 1))*mkvc(vh[1]*np.ones((n[2]+1, 1)).T)
+                    l3 = np.ones((n[0]+1, 1))*mkvc(np.ones((n[1]+1, 1))*vh[2].T)
+                    self._edge = np.r_[mkvc(l1), mkvc(l2), mkvc(l3)]
+            return self._edge
+        return locals()
+    _edge = None
+    edge = property(**edge())
+
 
 if __name__ == '__main__':
     print('Welcome to tensor mesh!')