== MS_cijkl2cij

 MS_CIJKL2CIJ - Convert from elastic tensor to Voigt elasticity matrix

 // Part of MSAT - The Matlab Seismic Anisotropy Toolkit //

 Converts between a 3x3x3x3 tensor representation and a 6x6 Voigt 
     representation of anisotropic elasticity. 

 [C] = MS_cijkl2cij(CC)

 Usage: 
     CC must be a rank 4 array with size (3,3,3,3). The
     returned array C will be rank 2 with size (6,6). The elasticity
     matrix representation is used as input for almost all MSAT functions.

 Notes:
     Do not use this function for the elastic compliance as additional
     terms are needed in this case.

 See also: MS_cij2cijkl
