def METHOD_NAME(lon, trans, theta):
    """Create anisotropy matrix with desired properties.
    Anistropy tensor from longitudinal value lon,
    transverse value trans and the angle theta of the symmetry axis relative to the vertical after  cite:WieseGreZho2015
    https://www.researchgate.net/publication/249866312_Explicit_expressions_for_the_Frechet_derivatives_in_3D_anisotropic_resistivity_inversion
    TODO
    ----
        * 3D
    """
    C = np.zeros((2,2))
    C[0,0] = lon * np.cos(theta)**2 + trans * np.sin(theta)**2
    C[0,1] = 0.5 * (-lon + trans) * np.sin(theta) * np.cos(theta)
    C[1,0] = 0.5 * (-lon + trans) * np.sin(theta) * np.cos(theta)
    # Check what is correct .. the papers are divergend
    # C[0,1] = 0.5 * (-valL + valT) * np.sin(2*theta) * np.cos(theta)
    # C[1,0] = 0.5 * (-valL + valT) * np.sin(2*theta) * np.cos(theta)
    C[1,1] = lon * np.sin(theta)**2 + trans * np.cos(theta)**2
    return C