For a given elastic stiffness tetrad an algorithm is provided to determine the distance of this particular tetrad to all tetrads of a prescribed symmetry class. If the particular tetrad already belongs to this class then the distance is zero and the presentation of this tetrad with respect to the symmetry axes can be obtained. If the distance turns out to be positive, the algorithm provides a measure to see how close it is to this symmetry class. Moreover, the closest element of this class to it is also determined. This applies in cases where the tetrad is not ideal due to scattering of its measurement. The algorithm is entirely algebraic and applies to all symmetry classes, although the isotropic and the cubic class need a different treatment from all other classes.

中文翻译：

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刚度到对称类的距离

对于给定的弹性刚度四分体，提供了一种算法来确定该特定四分体与指定对称类的所有四分体的距离。如果特定四分体已经属于此类，则距离为零，并且可以获得该四分体相对于对称轴的表示。如果距离结果为正，则该算法会提供一种度量以查看它与该对称类的接近程度。此外，还确定了该类中与其最近的元素。这适用于四分体由于其测量的散射而不理想的情况。该算法完全是代数的，适用于所有对称类，尽管各向同性和三次类需要与所有其他类不同的处理方式。