Notes for ROT

1. Applies plane rotation.
2. An index file input line looks like:

   <ID> <C> <S> <incX> <incY> <source file> <author name>
   

3. Will never be called with $C = 1, S = 0$ (ROT is no-op for this case)
4. For complex, if both vectors have unit stride, the real routine is called with 2*N.