Quasiperiodic function
Definition 1
A function is said to be quasiperiodic if it can be expressed in terms of a basic frequency and for each there exists a -periodic function such that the following holds .
Explanation
A quasiperiodic function is not literally a periodic function, but it possesses similar properties. For instance, the defined as follows is a quasiperiodic function.
On the other hand, a quasiperiodic function with infinitely many basic frequencies may also be referred to as an almost periodic function.
Wiggins. (2003). Introduction to Applied Nonlinear Dynamical Systems and Chaos Second Edition(2nd Edition): p803. ↩︎