nodal gradient

SimPEG/Mesh/NewTreeMesh.py

@@ -909,9 +909,27 @@ class TreeMesh(BaseMesh):
             C = sp.csr_matrix((V,(I,J)), shape=(self.nF, self.nE))
             S = self.area
             L = self.edge
-            self._edgeCurl = sdiag(1/S)*C*sdiag(L)
+            self._edgeCurl = sdiag(1.0/S)*C*sdiag(L)
         return self._edgeCurl
 
+    @property
+    def nodalGrad(self):
+        if getattr(self, '_nodalGrad', None) is None:
+            self.number()
+            # TODO: Preallocate!
+            I, J, V = [], [], []
+            E = self._edges
+            N = self._nodes
+            activeEdges = E[:,ACTIVE] == 1
+            for edge in E[activeEdges]:
+                I += [edge[NUM], edge[NUM]]
+                J += [N[edge[ENODE0], NUM], N[edge[ENODE1], NUM]]
+                V += [-1, 1]
+            G = sp.csr_matrix((V,(I,J)), shape=(self.nE, self.nN))
+            L = self.edge
+            self._nodalGrad = sdiag(1.0/L)*G
+        return self._nodalGrad
+
     def plotGrid(self, ax=None, text=True, showIt=False):
         import matplotlib.pyplot as plt
 

SimPEG/Tests/test_NewTreeMesh.py

@@ -86,9 +86,9 @@ class SimpleOctreeOperatorTests(unittest.TestCase):
         self.assertAlmostEqual((self.tM.faceDiv - self.oM.faceDiv).toarray().sum(), 0)
         self.assertAlmostEqual((self.tM2.faceDiv - self.oM2.faceDiv).toarray().sum(), 0)
 
-    # def test_nodalGrad(self):
-    #     self.assertAlmostEqual((self.tM.nodalGrad - self.oM.nodalGrad).toarray().sum(), 0)
-    #     self.assertAlmostEqual((self.tM2.nodalGrad - self.oM2.nodalGrad).toarray().sum(), 0)
+    def test_nodalGrad(self):
+        self.assertAlmostEqual((self.tM.nodalGrad - self.oM.nodalGrad).toarray().sum(), 0)
+        self.assertAlmostEqual((self.tM2.nodalGrad - self.oM2.nodalGrad).toarray().sum(), 0)
 
     def test_edgeCurl(self):
         self.assertAlmostEqual((self.tM.edgeCurl - self.oM.edgeCurl).toarray().sum(), 0)