Need this type of sine wave animation without the cuts as like it is a wire. How to make? [Link for the video

https://drive.google.com/open?id=1tTYkHJjxdJkd1SB3rI5Rcoxq1GttfyQU

this is the link for the video that i have already made but it have cuts





The answer you posted was similar to the required animation by me.
But The spline is in square shape, I need a circular one. Can u help me with that.

and also how can we decrease the speed or increase the length of the spline.
The curve you are trying to create can be described by the following parametric equation:

$$
\begin{bmatrix}
p\\
\alpha p \sin({\beta t + p})
\end{bmatrix}
$$

Where $\beta$ and $\alpha$ are arbitrary constants, $t$ is the time, and $p$ is the parameter. We can implement this in Animation Nodes as follows: