update example name --> based on mesh

SimPEG/Examples/Mesh_Basic_ForwardDC.py

@@ -0,0 +1,58 @@
+from SimPEG import Mesh, Utils, np, SolverLU
+
+def run(plotIt=True):
+
+    """
+        Mesh: Basic Forward 2D DC Resistivity
+        =====================================
+
+        2D DC forward modeling example with Tensor and Curvilinear Meshes
+    """
+
+    # Step1: Generate Tensor and Curvilinear Mesh
+    sz = [40,40]
+    tM = Mesh.TensorMesh(sz)
+    rM = Mesh.CurvilinearMesh(Utils.meshutils.exampleLrmGrid(sz,'rotate'))
+
+    # Step2: Direct Current (DC) operator
+    def DCfun(mesh, pts):
+        D = mesh.faceDiv
+        sigma = 1e-2*np.ones(mesh.nC)
+        MsigI = mesh.getFaceInnerProduct(sigma, invProp=True, invMat=True)
+        A = -D*MsigI*D.T
+        A[-1,-1] /= mesh.vol[-1] # Remove null space
+        rhs = np.zeros(mesh.nC)
+        txind = Utils.meshutils.closestPoints(mesh, pts)
+        rhs[txind] = np.r_[1,-1]
+        return A, rhs
+
+    pts = np.vstack((np.r_[0.25, 0.5], np.r_[0.75, 0.5]))
+
+    #Step3: Solve DC problem (LU solver)
+    AtM, rhstM = DCfun(tM, pts)
+    AinvtM = SolverLU(AtM)
+    phitM = AinvtM*rhstM
+
+    ArM, rhsrM = DCfun(rM, pts)
+    AinvrM = SolverLU(ArM)
+    phirM = AinvrM*rhsrM
+
+    if not plotIt: return
+
+    import matplotlib.pyplot as plt
+
+    #Step4: Making Figure
+    fig, axes = plt.subplots(1,2,figsize=(12*1.2,4*1.2))
+    vmin, vmax = phitM.min(), phitM.max()
+    dat = tM.plotImage(phitM, ax=axes[0], clim=(vmin, vmax), grid=True)
+    dat = rM.plotImage(phirM, ax=axes[1], clim=(vmin, vmax), grid=True)
+    cb = plt.colorbar(dat[0], ax=axes[0]); cb.set_label("Voltage (V)")
+    cb = plt.colorbar(dat[0], ax=axes[1]); cb.set_label("Voltage (V)")
+
+    axes[0].set_title('TensorMesh')
+    axes[1].set_title('CurvilinearMesh')
+    plt.show()
+
+
+if __name__ == '__main__':
+    run()