Added tests for G.

simpegEM/Tests/test_forward_EMproblem.py

@@ -39,6 +39,34 @@ class TDEM_bTests(unittest.TestCase):
        diff = np.linalg.norm(bz_calc.flatten() - bz_ana.flatten())/np.linalg.norm(bz_ana.flatten())
        self.assertTrue(diff<0.05)
 
+
+class TDEM_bDerivTests(unittest.TestCase):
+
+    def setUp(self):
+
+       cs = 5.
+       ncx = 20
+       ncy = 6
+       npad = 20
+       hx = Utils.meshTensors(((0,cs), (ncx,cs), (npad,cs)))
+       hy = Utils.meshTensors(((npad,cs), (ncy,cs), (npad,cs)))
+       mesh = Mesh.Cyl1DMesh([hx,hy], -hy.sum()/2)
+       model = Model.Vertical1DModel(mesh)
+
+       opts = {'txLoc':0.,
+               'txType':'VMD_MVP',
+               'rxLoc':np.r_[150., 0.],
+               'rxType':'bz',
+               'timeCh':np.logspace(-4,-2,20),
+               }
+       self.dat = EM.TDEM.DataTDEM1D(**opts)
+
+       self.prb = EM.TDEM.ProblemTDEM_b(mesh, model)
+       self.prb.setTimes([1e-5, 5e-5, 2.5e-4], [10, 10, 10])
+       self.sigma = np.ones(mesh.nCz)*1e-8
+       self.sigma[mesh.vectorCCz<0] = 0.1
+       self.prb.pair(self.dat)
+
     def test_AhVec(self):
         """
             Test that fields and AhVec produce consistent results
@@ -55,7 +83,21 @@ class TDEM_bTests(unittest.TestCase):
             self.assertTrue(np.linalg.norm(Ahu.get_e(i))/np.linalg.norm(u.get_e(i)) < 1.e-2)
 
 
+    def test_DerivG(self):
+        """
+            Test the derivative of c with respect to sigma
+        """
 
+        # Random model and perturbation
+        sigma = np.random.rand(self.prb.mesh.nCz)
+        f = self.prb.fields(sigma)
+        dm = np.random.rand(self.prb.mesh.nCz)
+        h = 1.
+
+        a = np.linalg.norm(self.prb.AhVec(sigma+h*dm, f).fieldVec() - self.prb.AhVec(sigma, f).fieldVec())
+        b = np.linalg.norm(self.prb.AhVec(sigma+h*dm, f).fieldVec() - self.prb.AhVec(sigma, f).fieldVec() - h*self.prb.G(sigma, dm, u=f).fieldVec())
+        # Assuming that the gradient is exact to machine precision
+        self.assertTrue(b<1e-16)
 
 
 if __name__ == '__main__':