MS_rotEuler
MS_ROTEULER - Rotate an elasticity matrix using Bunge's Euler angles
// Part of MSAT - The Matlab Seismic Anisotropy Toolkit //
Rotate one or more elasticity matrices usign Bunge's Euler angles
[ CC ] = MS_rotEuler( C, phi1, theta, phi2 )
Usage: For three angles in degrees (phi1, theta, phi2) representing a rotation in Bunge convention rotate the elasticity matrix C. All variables can be arrays or scalars but (1) the angles must all be the same length and (2) either C or all the angles must be scalars unless they are the same length.
Notes: In the context of this function the term 'Euler angle' is used in the sense common in texture analysis not computer graphics etc. where the three angles are rotations around a fixes axis system (see MS_rot3 for this case). In the (Bunge) convention used here the object (crystal) reference frame is first assumed to be alligned with the sample reference frame. The object is then rotated around the common z axis by an angle phi1. The second rotation (theta) is about the object's x axis (which is no longer parallel to the external x axis). The third rotation, phi2, is about the samples z axis (which, by this point, is not paralell with the external z axis). See Figure 5 of Bunge 1985 for a graphical example.
References: Bunge, H. J. (1985) "Representaton of Preferred Orientations" in H.-R. Wenk (ed.) "Preferred Orientation in Deformed Metals and Rocks: An Introduction to Modern Texture Analysis" Academic Press inc. Orlando.
See also: MS_ROT3 MS_ROTR