(defun multiply-vector-in-place (initial-state function-name)
  (declare (type (array (complex double-float) *) initial-state)
           (ftype (function (integer) (complex double-float)) function-name))
  (loop for i from 0 below (length initial-state)
        do (setf (aref initial-state i)
                 (* (aref initial-state i)
                    (funcall function-name i)))))