This code demonstrates the use of MSAT to calculate derived properties from a set of elastic constants. The model used is a model of lowermost mantle anisotropy from Walker et al (2011), specifically TX2008.V1.P010.dat. See www1.gly.bris.ac.uk/CoMITAC/software.htm for details.

The source code for this example are contained in the file lmm_anisotropy_example.m in the examples/lowermost directory distributed with MSAT. This directory also contains the data file needed to run the example.

Much of the example is similar to the calculations described in example 2. However, one important additional calculation is performed, specifically the symmetry based analysis of Browaeys and Chevrot (2004). This analysis is performed in three stages. First MS_axes is used to find the principal axes of the stress tensor needed to cause an isotropic strain and the elasticity tensor Chere rotated to be aligned with this. The second step uses MS_decomp to split the matrix into contributions from the six symmetry classes. MS_norms then calculates the Euclidean norm of each contributing elasticity matrix before, for this application, the percentage of the sum of the norms that is contributed from the hexagonal matrix is calculated.

         ChereR = MS_axes(Chere) ;
         [C_iso,C_hex,C_tet,C_ort,C_mon,C_tri] = MS_decomp(ChereR);
         P = MS_norms(ChereR,C_iso,C_hex,C_tet,C_ort,C_mon,C_tri) ;
         SumA = sum(P(2:end)) ;
         PercH(ila(i),ilo(i)) = P(2)./SumA ;