def setUp(self):

        cs = 12.5
        nc = 500 / cs + 1
        hx = [(cs, 0, -1.3), (cs, nc), (cs, 0, 1.3)]
        hy = [(cs, 0, -1.3), (cs, int(nc / 2 + 1)), (cs, 0, 1.3)]
        hz = [(cs, 0, -1.3), (cs, int(nc / 2 + 1))]
        mesh = Mesh.TensorMesh([hx, hy, hz], 'CCN')
        sighalf = 1e-2
        sigma = np.ones(mesh.nC) * sighalf
        p0 = np.r_[-50., 50., -50.]
        p1 = np.r_[50., -50., -150.]
        blk_ind = Utils.ModelBuilder.getIndicesBlock(p0, p1, mesh.gridCC)
        sigma[blk_ind] = 1e-3
        eta = np.zeros_like(sigma)
        eta[blk_ind] = 0.1

        nElecs = 5
        x_temp = np.linspace(-250, 250, nElecs)
        aSpacing = x_temp[1] - x_temp[0]
        y_temp = 0.
        xyz = Utils.ndgrid(x_temp, np.r_[y_temp], np.r_[0.])
        srcList = DC.Utils.WennerSrcList(nElecs, aSpacing)
        survey = DC.SurveyIP(srcList)
        imap = Maps.IdentityMap(mesh)
        problem = DC.ProblemIP(mesh, sigma=sigma, mapping=imap)
        problem.pair(survey)

        try:
            from pymatsolver import MumpsSolver
            problem.Solver = MumpsSolver
        except ImportError, e:
            problem.Solver = SolverLU
Example #2
0
class IPforwardTests(unittest.TestCase):
    def test_IPforward(self):

        cs = 12.5
        nc = 200 / cs + 1
        hx = [(cs, 7, -1.3), (cs, nc), (cs, 7, 1.3)]
        hy = [(cs, 7, -1.3), (cs, int(nc / 2 + 1)), (cs, 7, 1.3)]
        hz = [(cs, 7, -1.3), (cs, int(nc / 2 + 1))]
        mesh = Mesh.TensorMesh([hx, hy, hz], 'CCN')
        sighalf = 1e-2
        sigma = np.ones(mesh.nC) * sighalf
        p0 = np.r_[-50., 50., -50.]
        p1 = np.r_[50., -50., -150.]
        blk_ind = Utils.ModelBuilder.getIndicesBlock(p0, p1, mesh.gridCC)
        sigma[blk_ind] = 1e-3
        eta = np.zeros_like(sigma)
        eta[blk_ind] = 0.1
        sigmaInf = sigma.copy()
        sigma0 = sigma * (1 - eta)

        nElecs = 11
        x_temp = np.linspace(-100, 100, nElecs)
        aSpacing = x_temp[1] - x_temp[0]
        y_temp = 0.
        xyz = Utils.ndgrid(x_temp, np.r_[y_temp], np.r_[0.])
        srcList = DC.Utils.WennerSrcList(nElecs, aSpacing)
        survey = DC.SurveyDC(srcList)

        imap = Maps.IdentityMap(mesh)
        problem = DC.ProblemDC_CC(mesh, mapping=imap)

        try:
            from pymatsolver import MumpsSolver
            solver = MumpsSolver
        except ImportError, e:
            solver = SolverLU

        problem.Solver = solver
        problem.pair(survey)

        phi0 = survey.dpred(sigma0)
        phiInf = survey.dpred(sigmaInf)

        phiIP_true = phi0 - phiInf

        surveyIP = DC.SurveyIP(srcList)
        problemIP = DC.ProblemIP(mesh, sigma=sigma)
        problemIP.pair(surveyIP)

        problemIP.Solver = solver

        phiIP_approx = surveyIP.dpred(eta)

        err = np.linalg.norm(phiIP_true -
                             phiIP_approx) / np.linalg.norm(phiIP_true)

        self.assertTrue(err < 0.02)