Subscripted indexing (unimplemented function)
(Quaternion overloading of standard MATLAB® function)
r = subsindex(a)
subsindex is an overloading of a MATLAB® function that plays an essential role in subscripted indexing. Since it does not make sense to index an array using a quaternion, this function is not needed, but it is implemented in order to trap cases where the user defines variables called s, x, y, or z, since in these cases if the user enters s(a), expecting to extract the scalar part of a, MATLAB® will try to index the variable s using the quaternion a. The function will output an error message directing the user to the source of the problem.