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OGS
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OGS
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A local coordinate system used for tensor transformations.
It offers a simple way for input of anisotropic tensors w.r.t. a coordinate system. The basis vectors form a transformation matrix \(R = (e_0, e_1, e_2)\). For a given anisotropic tensor \(A\) parameter with the corresponding [tag] use_local_coordinate_system the tensor is rotated according to the formula: \(A' = R\cdot A\cdot R^T\).
For computations in transverse isotropic material models, we can create a coordinate system with only one base, where the last base is explicitly given. The other bases are set as implicit and computed from the given base as follows:
unit_direction, is set as the third base, \({\vec e}_2\). An arbitrary unit vector orthogonal to \({\vec e}_2\) is selected as the second base \(e_1\), and the first base \({\vec e}_0\) is calculated as \({\vec e}_0 = {\vec e}_1 \times {\vec e}_2\). 
1.12.0