def Laplacian(dims, dirs=(0, 1), weights=(1, 1), sampling=(1, 1), edge=False, dtype='float64'): r"""Laplacian. Apply second-order centered Laplacian operator to a multi-dimensional array (at least 2 dimensions are required) Parameters ---------- dims : :obj:`tuple` Number of samples for each dimension. dirs : :obj:`tuple`, optional Directions along which laplacian is applied. weights : :obj:`tuple`, optional Weight to apply to each direction (real laplacian operator if ``weights=[1,1]``) sampling : :obj:`tuple`, optional Sampling steps for each direction edge : :obj:`bool`, optional Use reduced order derivative at edges (``True``) or ignore them (``False``) dtype : :obj:`str`, optional Type of elements in input array. Returns ------- l2op : :obj:`pylops.LinearOperator` Laplacian linear operator Notes ----- The Laplacian operator applies a second derivative along two directions of a multi-dimensional array. For simplicity, given a two dimensional array, the Laplacian is: .. math:: y[i, j] = (x[i+1, j] + x[i-1, j] + x[i, j-1] +x[i, j+1] - 4x[i, j]) / (dx*dy) """ l2op = weights[0] * SecondDerivative(np.prod(dims), dims=dims, dir=dirs[0], sampling=sampling[0], edge=edge, dtype=dtype) l2op += weights[1] * SecondDerivative(np.prod(dims), dims=dims, dir=dirs[1], sampling=sampling[1], edge=edge, dtype=dtype) return aslinearoperator(l2op)
def Laplacian(dims, dirs=(0, 1), weights=(1, 1), sampling=(1, 1), dtype='float32'): r"""Laplacian. Apply second-order centered laplacian operator to a multi-dimensional array (at least 2 dimensions are required) Parameters ---------- dims : :obj:`tuple` Number of samples for each dimension. dirs : :obj:`tuple`, optional Directions along which laplacian is applied. weights : :obj:`tuple`, optional Weight to apply to each direction (real laplacian operator if ``weights=[1,1]``) sampling : :obj:`tuple`, optional Sampling steps ``dx`` and ``dy`` for each direction dtype : :obj:`str`, optional Type of elements in input array. Returns ------- l2op : LinearOperator Laplacian linear operator Notes ----- The Laplacian operator applies a second derivative along two directions of a multi-dimensional array. For simplicity, given a two dimensional array, the laplacin is: .. math:: y[i, j] = (x[i+1, j] + x[i-1, j] + x[i, j-1] +x[i, j+1] - 4x[i, j]) / (dx*dy) """ l2op = weights[0]*SecondDerivative(np.prod(dims), dims=dims, dir=dirs[0], sampling=sampling[0], dtype=dtype) + \ weights[1]*SecondDerivative(np.prod(dims), dims=dims, dir=dirs[1], sampling=sampling[1], dtype=dtype) return l2op
def test_SecondDerivative(par): """Dot-test and comparison with Pylops for SecondDerivative operator """ np.random.seed(10) x = par['dx'] * np.arange(par['nx']) y = par['dy'] * np.arange(par['ny']) z = par['dz'] * np.arange(par['nz']) xx, yy = np.meshgrid(x, y) # produces arrays of size (ny,nx) xxx, yyy, zzz = np.meshgrid(x, y, z) # produces arrays of size (ny,nx,nz) # 1d dD2op = dSecondDerivative(par['nx'], sampling=par['dx'], compute=(True, True), dtype='float32') D2op = SecondDerivative(par['nx'], sampling=par['dx'], edge=False, dtype='float32') assert dottest(dD2op, par['nx'], par['nx'], chunks=(par['nx'] // 2 + 1, par['nx'] // 2 + 1), tol=1e-3) x = da.from_array(x, chunks=par['nx'] // 2 + 1) dy = dD2op * x y = D2op * x.compute() assert_array_almost_equal(y[1:-1], dy[1:-1], decimal=1) # 2d - derivative on 1st direction dD2op = dSecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=0, sampling=par['dy'], compute=(False, False), dtype='float32') D2op = SecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=0, sampling=par['dy'], edge=False, dtype='float32') assert dottest(dD2op, par['ny'] * par['nx'], par['ny'] * par['nx'], chunks=((par['ny'] // 2 + 1) * (par['nx'] // 2 + 1), (par['ny'] // 2 + 1) * (par['nx'] // 2 + 1)), tol=1e-3) xx = da.from_array(xx, chunks=(par['ny'] // 2 + 1, par['nx'] // 2 + 1)) dy = dD2op * xx.ravel() y = D2op * xx.compute().ravel() assert_array_almost_equal(y.reshape(par['ny'], par['nx'])[1:-1, 1:-1], dy.reshape(par['ny'], par['nx'])[1:-1, 1:-1], decimal=1) # 2d - derivative on 2nd direction dD2op = dSecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=1, sampling=par['dy'], compute=(False, False), dtype='float32') D2op = SecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=1, sampling=par['dx'], edge=False, dtype='float32') assert dottest(dD2op, par['ny'] * par['nx'], par['ny'] * par['nx'], chunks=((par['ny'] // 2 + 1) * (par['nx'] // 2 + 1), (par['ny'] // 2 + 1) * (par['nx'] // 2 + 1)), tol=1e-3) yy = da.from_array(yy, chunks=(par['ny'] // 2 + 1, par['nx'] // 2 + 1)) dy = dD2op * yy.ravel() y = D2op * yy.compute().ravel() assert_array_almost_equal(y.reshape(par['ny'], par['nx'])[1:-1, 1:-1], dy.reshape(par['ny'], par['nx'])[1:-1, 1:-1], decimal=1) # 3d - derivative on 1st direction dD2op = dSecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['ny'], par['nx'], par['nz']), dir=0, sampling=par['dy'], compute=(False, False), dtype='float32') D2op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['ny'], par['nx'], par['nz']), dir=0, sampling=par['dy'], edge=False, dtype='float32') assert dottest(dD2op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], chunks=((par['ny'] // 2 + 1) * (par['nx'] // 2 + 1), (par['ny'] // 2 + 1) * (par['nx'] // 2 + 1)), tol=1e-3) xxx = da.from_array(xxx, chunks=(par['nz'] // 2 + 1, par['ny'] // 2 + 1, par['nx'] // 2 + 1)) dy = dD2op * xxx.ravel() y = D2op * xxx.compute().ravel() assert_array_almost_equal(y.reshape(par['nz'], par['ny'], par['nx'])[1:-1, 1:-1, 1:-1], dy.reshape(par['nz'], par['ny'], par['nx'])[1:-1, 1:-1, 1:-1], decimal=1) """
def test_SecondDerivative(par): """Dot-test and forward for SecondDerivative operator """ # 1d gD1op = gSecondDerivative(par['nx'], sampling=par['dx'], dtype=torch.float32) assert dottest(gD1op, par['nx'], par['nx'], tol=1e-3) x = torch.from_numpy( (par['dx'] * np.arange(par['nx'], dtype='float32'))**2) D1op = SecondDerivative(par['nx'], sampling=par['dx'], dtype='float32') assert_array_equal((gD1op * x)[1:-1], (D1op * x.cpu().numpy())[1:-1]) # 2d - derivative on 1st direction gD1op = gSecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=0, sampling=par['dy'], dtype=torch.float32) assert dottest(gD1op, par['ny'] * par['nx'], par['ny'] * par['nx'], tol=1e-3) x = torch.from_numpy( (np.outer((par['dy'] * np.arange(par['ny']))**2, np.ones(par['nx']))).astype(dtype='float32')) D1op = SecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=0, sampling=par['dy'], dtype='float32') gy = (gD1op * x.view(-1)).reshape(par['ny'], par['nx']).cpu().numpy() y = (D1op * x.view(-1).cpu().numpy()).reshape(par['ny'], par['nx']) assert_array_equal(gy[1:-1], y[1:-1]) # 2d - derivative on 2nd direction gD1op = gSecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=1, sampling=par['dy'], dtype=torch.float32) assert dottest(gD1op, par['ny'] * par['nx'], par['ny'] * par['nx'], tol=1e-3) x = torch.from_numpy( (np.outer((par['dy'] * np.arange(par['ny']))**2, np.ones(par['nx']))).astype(dtype='float32')) D1op = SecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=1, sampling=par['dy'], dtype='float32') gy = (gD1op * x.view(-1)).reshape(par['ny'], par['nx']).cpu().numpy() y = (D1op * x.view(-1).cpu().numpy()).reshape(par['ny'], par['nx']) assert_array_equal(gy[:, 1:-1], y[:, 1:-1]) # 3d - derivative on 1st direction gD1op = gSecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=0, sampling=par['dz'], dtype=torch.float32) assert dottest(gD1op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], tol=1e-3) x = torch.from_numpy( (np.outer((par['dz'] * np.arange(par['nz']))**2, np.ones((par['ny'], par['nx']))).astype(dtype='float32'))) D1op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=0, sampling=par['dz'], dtype='float32') gy = (gD1op * x.view(-1)).reshape(par['nz'], par['ny'], par['nx']).cpu().numpy() y = (D1op * x.view(-1).cpu().numpy()).reshape(par['nz'], par['ny'], par['nx']) assert_array_almost_equal(gy[1:-1], y[1:-1], decimal=5) # 3d - derivative on 2nd direction gD1op = gSecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=1, sampling=par['dy'], dtype=torch.float32) assert dottest(gD1op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], tol=1e-3) x = torch.from_numpy((np.outer( (par['dz'] * np.arange(par['nz']))**2, np.ones( (par['ny'], par['nx']))).reshape(par['nz'], par['ny'], par['nx'])).astype(dtype='float32')) D1op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=1, sampling=par['dy'], dtype='float32') gy = (gD1op * x.view(-1)).reshape(par['nz'], par['ny'], par['nx']).cpu().numpy() y = (D1op * x.view(-1).cpu().numpy()).reshape(par['nz'], par['ny'], par['nx']) assert_array_almost_equal(gy[1:-1], y[1:-1], decimal=5) # 3d - derivative on 3rd direction gD1op = gSecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=2, sampling=par['dx'], dtype=torch.float32) assert dottest(gD1op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], tol=1e-3) x = torch.from_numpy((np.outer( (par['dz'] * np.arange(par['nz']))**2, np.ones( (par['ny'], par['nx']))).reshape(par['nz'], par['ny'], par['nx'])).astype(dtype='float32')) D1op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=2, sampling=par['dx'], dtype='float32') gy = (gD1op * x.view(-1)).reshape(par['nz'], par['ny'], par['nx']).cpu().numpy() y = (D1op * x.view(-1).cpu().numpy()).reshape(par['nz'], par['ny'], par['nx']) assert_array_almost_equal(gy[1:-1], y[1:-1], decimal=5)
def test_SecondDerivative(par): """Dot-test and forward for SecondDerivative operator The test is based on the fact that the central stencil is exact for polynomials of degree 3. """ x = par['dx'] * np.arange(par['nx']) y = par['dy'] * np.arange(par['ny']) z = par['dz'] * np.arange(par['nz']) xx, yy = np.meshgrid(x, y) # produces arrays of size (ny,nx) xxx, yyy, zzz = np.meshgrid(x, y, z) # produces arrays of size (ny,nx,nz) # 1d D2op = SecondDerivative(par['nx'], sampling=par['dx'], edge=par['edge'], dtype='float32') assert dottest(D2op, par['nx'], par['nx'], tol=1e-3) # polynomial f(x) = x^3, f''(x) = 6x f = x**3 dfana = 6 * x df = D2op * f assert_array_almost_equal(df[1:-1], dfana[1:-1], decimal=1) # 2d - derivative on 1st direction D2op = SecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=0, sampling=par['dy'], edge=par['edge'], dtype='float32') assert dottest(D2op, par['ny'] * par['nx'], par['ny'] * par['nx'], tol=1e-3) # polynomial f(x,y) = y^3, f_{yy}(x,y) = 6y f = yy**3 dfana = 6 * yy df = D2op * f.flatten() df = df.reshape(par['ny'], par['nx']) assert_array_almost_equal(df[1:-1, :], dfana[1:-1, :], decimal=1) # 2d - derivative on 2nd direction D2op = SecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=1, sampling=par['dx'], edge=par['edge'], dtype='float32') assert dottest(D2op, par['ny'] * par['nx'], par['ny'] * par['nx'], tol=1e-3) # polynomial f(x,y) = x^3, f_{xx}(x,y) = 6x f = xx**3 dfana = 6 * xx df = D2op * f.flatten() df = df.reshape(par['ny'], par['nx']) assert_array_almost_equal(df[:, 1:-1], dfana[:, 1:-1], decimal=1) # 3d - derivative on 1st direction D2op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['ny'], par['nx'], par['nz']), dir=0, sampling=par['dy'], edge=par['edge'], dtype='float32') assert dottest(D2op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], tol=1e-3) # polynomial f(x,y,z) = y^3, f_{yy}(x,y,z) = 6y f = yyy**3 dfana = 6 * yyy df = D2op * f.flatten() df = df.reshape(par['ny'], par['nx'], par['nz']) assert_array_almost_equal(df[1:-1, :, :], dfana[1:-1, :, :], decimal=1) # 3d - derivative on 2nd direction D2op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['ny'], par['nx'], par['nz']), dir=1, sampling=par['dx'], edge=par['edge'], dtype='float32') assert dottest(D2op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], tol=1e-3) # polynomial f(x,y,z) = x^3, f_{xx}(x,y,z) = 6x f = xxx**3 dfana = 6 * xxx df = D2op * f.flatten() df = df.reshape(par['ny'], par['nx'], par['nz']) assert_array_almost_equal(df[:, 1:-1, :], dfana[:, 1:-1, :], decimal=1) # 3d - derivative on 3rd direction D2op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['ny'], par['nx'], par['nz']), dir=2, sampling=par['dz'], edge=par['edge'], dtype='float32') assert dottest(D2op, par['nz'] * par['ny'] * par['nx'], par['ny'] * par['nx'] * par['nz'], tol=1e-3) # polynomial f(x,y,z) = z^3, f_{zz}(x,y,z) = 6z f = zzz**3 dfana = 6 * zzz df = D2op * f.flatten() df = df.reshape(par['ny'], par['nx'], par['nz']) assert_array_almost_equal(df[:, :, 1:-1], dfana[:, :, 1:-1], decimal=1)
def test_SecondDerivative(par): """Dot-test and forward for SecondDerivative operator """ # 1d D2op = SecondDerivative(par['nx'], sampling=par['dx'], dtype='float32') assert dottest(D2op, par['nx'], par['nx'], tol=1e-3) x = (par['dx'] * np.arange(par['nx']))**3 yana = 6 * par['dx']**2 * np.arange(par['nx']) y = D2op * x assert_array_almost_equal(y[2:-2], yana[2:-2], decimal=1) # 2d - derivative on 1st direction D2op = SecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=0, sampling=par['dy'], dtype='float32') assert dottest(D2op, par['ny'] * par['nx'], par['ny'] * par['nx'], tol=1e-3) x = np.outer((par['dy'] * np.arange(par['ny']))**3, np.ones(par['nx'])) yana = np.outer(6 * par['dy']**2 * np.arange(par['ny']), np.ones(par['nx'])) y = D2op * x.flatten() y = y.reshape(par['ny'], par['nx']) assert_array_almost_equal(y[1:-1], yana[1:-1], decimal=1) # 2d - derivative on 2nd direction D2op = SecondDerivative(par['ny'] * par['nx'], dims=(par['ny'], par['nx']), dir=1, sampling=par['dx'], dtype='float32') assert dottest(D2op, par['ny'] * par['nx'], par['ny'] * par['nx'], tol=1e-3) x = np.outer((par['dy'] * np.arange(par['ny']))**3, np.ones(par['nx'])) yana = np.zeros((par['ny'], par['nx'])) y = D2op * x.flatten() y = y.reshape(par['ny'], par['nx']) assert_array_almost_equal(y[1:-1], yana[1:-1], decimal=1) # 3d - derivative on 1st direction D2op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=0, sampling=par['dz'], dtype='float32') assert dottest(D2op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], tol=1e-3) x = np.outer((par['dz'] * np.arange(par['nz']))**3, np.ones( (par['ny'], par['nx']))).reshape(par['nz'], par['ny'], par['nx']) yana = np.outer(6 * par['dz']**2 * np.arange(par['nz']), np.ones((par['ny'], par['nx']))).reshape(par['nz'], par['ny'], par['nx']) y = D2op * x.flatten() y = y.reshape(par['nz'], par['ny'], par['nx']) assert_array_almost_equal(y[1:-1], yana[1:-1], decimal=1) # 3d - derivative on 2nd direction D2op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=1, sampling=par['dy'], dtype='float32') assert dottest(D2op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], tol=1e-3) x = np.outer((par['dz'] * np.arange(par['nz']))**3, np.ones( (par['ny'], par['nx']))).reshape(par['nz'], par['ny'], par['nx']) yana = np.zeros((par['nz'], par['ny'], par['nx'])) y = D2op * x.flatten() y = y.reshape(par['nz'], par['ny'], par['nx']) assert_array_almost_equal(y[1:-1], yana[1:-1], decimal=1) # 3d - derivative on 3rd direction D2op = SecondDerivative(par['nz'] * par['ny'] * par['nx'], dims=(par['nz'], par['ny'], par['nx']), dir=2, sampling=par['dx'], dtype='float32') assert dottest(D2op, par['nz'] * par['ny'] * par['nx'], par['nz'] * par['ny'] * par['nx'], tol=1e-3) x = np.outer((par['dz'] * np.arange(par['nz']))**3, np.ones( (par['ny'], par['nx']))).reshape(par['nz'], par['ny'], par['nx']) yana = np.zeros((par['nz'], par['ny'], par['nx'])) y = D2op * x.flatten() y = y.reshape(par['nz'], par['ny'], par['nx']) assert_array_almost_equal(y[1:-1], yana[1:-1], decimal=1)
def Laplacian( dims, dirs=(0, 1), weights=(1, 1), sampling=(1, 1), edge=False, dtype="float64", kind="centered", ): r"""Laplacian. Apply second-order centered Laplacian operator to a multi-dimensional array. .. note:: At least 2 dimensions are required, use :py:func:`pylops.SecondDerivative` for 1d arrays. Parameters ---------- dims : :obj:`tuple` Number of samples for each dimension. dirs : :obj:`tuple`, optional Directions along which laplacian is applied. weights : :obj:`tuple`, optional Weight to apply to each direction (real laplacian operator if ``weights=[1,1]``) sampling : :obj:`tuple`, optional Sampling steps for each direction edge : :obj:`bool`, optional Use reduced order derivative at edges (``True``) or ignore them (``False``) for centered derivative dtype : :obj:`str`, optional Type of elements in input array. kind : :obj:`str`, optional Derivative kind (``forward``, ``centered``, or ``backward``) Returns ------- l2op : :obj:`pylops.LinearOperator` Laplacian linear operator Raises ------ ValueError If ``dirs``. ``weights``, and ``sampling`` do not have the same size Notes ----- The Laplacian operator applies a second derivative along two directions of a multi-dimensional array. For simplicity, given a two dimensional array, the Laplacian is: .. math:: y[i, j] = (x[i+1, j] + x[i-1, j] + x[i, j-1] +x[i, j+1] - 4x[i, j]) / (\Delta x \Delta y) """ if not (len(dirs) == len(weights) == len(sampling)): raise ValueError("dirs, weights, and sampling have different size") l2op = weights[0] * SecondDerivative( np.prod(dims), dims=dims, dir=dirs[0], sampling=sampling[0], edge=edge, kind=kind, dtype=dtype, ) for dir, samp, weight in zip(dirs[1:], sampling[1:], weights[1:]): l2op += weight * SecondDerivative( np.prod(dims), dims=dims, dir=dir, sampling=samp, edge=edge, dtype=dtype, ) return aslinearoperator(l2op)
def test_SecondDerivative_forward(par): """Dot-test for SecondDerivative operator (forward stencil). Note that the analytical expression cannot be validated in this case """ x = par["dx"] * np.arange(par["nx"]) y = par["dy"] * np.arange(par["ny"]) z = par["dz"] * np.arange(par["nz"]) xx, yy = np.meshgrid(x, y) # produces arrays of size (ny,nx) xxx, yyy, zzz = np.meshgrid(x, y, z) # produces arrays of size (ny,nx,nz) # 1d D2op = SecondDerivative(par["nx"], sampling=par["dx"], edge=par["edge"], kind="forward", dtype="float32") assert dottest(D2op, par["nx"], par["nx"], tol=1e-3) # 2d - derivative on 1st direction D2op = SecondDerivative( par["ny"] * par["nx"], dims=(par["ny"], par["nx"]), dir=0, sampling=par["dy"], edge=par["edge"], kind="forward", dtype="float32", ) assert dottest(D2op, par["ny"] * par["nx"], par["ny"] * par["nx"], tol=1e-3) # 2d - derivative on 2nd direction D2op = SecondDerivative( par["ny"] * par["nx"], dims=(par["ny"], par["nx"]), dir=1, sampling=par["dx"], edge=par["edge"], kind="forward", dtype="float32", ) assert dottest(D2op, par["ny"] * par["nx"], par["ny"] * par["nx"], tol=1e-3) # 3d - derivative on 1st direction D2op = SecondDerivative( par["nz"] * par["ny"] * par["nx"], dims=(par["ny"], par["nx"], par["nz"]), dir=0, sampling=par["dy"], edge=par["edge"], kind="forward", dtype="float32", ) assert dottest( D2op, par["nz"] * par["ny"] * par["nx"], par["nz"] * par["ny"] * par["nx"], tol=1e-3, ) # 3d - derivative on 2nd direction D2op = SecondDerivative( par["nz"] * par["ny"] * par["nx"], dims=(par["ny"], par["nx"], par["nz"]), dir=1, sampling=par["dx"], edge=par["edge"], kind="forward", dtype="float32", ) assert dottest( D2op, par["nz"] * par["ny"] * par["nx"], par["nz"] * par["ny"] * par["nx"], tol=1e-3, ) # 3d - derivative on 3rd direction D2op = SecondDerivative( par["nz"] * par["ny"] * par["nx"], dims=(par["ny"], par["nx"], par["nz"]), dir=2, sampling=par["dz"], edge=par["edge"], kind="forward", dtype="float32", ) assert dottest( D2op, par["nz"] * par["ny"] * par["nx"], par["ny"] * par["nx"] * par["nz"], tol=1e-3, )