Are periodic functions stationary processes, e.g. y=sin(t)?

Question

According to wikipedia, a stationary process (or strict(ly) stationary process or strong(ly) stationary process) is a stochastic process whose joint probability distribution does not change when shifted in time. Consequently, parameters such as the mean and variance, if they are present, also do not change over time and do not follow any trends.

So, is the sinusoidal function y=sin(t) is stationary process ?
Or more generally, are periodic functions stationary processes ?

Answer 1

First it has to be a "stochastic process". At least on the surface, $y=\sin(t)$ is deterministic, and not random. So it is not a stochastic process.

Answer 2

A deterministic process can be regarded as a special case of stochastic process. It seems that, among the deterministic processes, only constant processes are stationary.