| Code | Anisotropic_Axis_1_Inline_Direction |
| Name | Anisotropic Axis 1 Inline Direction |
| Parents | Property > Plane_Angle > Zenith_Angle |
| Description | Angle of first (or only) anisotropic symmetry axis, relative to vertical, measured in the in-line direction. Axis 1 on its own defines the rotational symmetry axis for transverse isotropy. If accompanied by Axis 2, they together define the symmetry planes for orthorhombic anisotropy. |
