You can start with any function $f(x)$. Then the graph of $g(x)=f(kx)$ is obtained from the graph of $f(x)$ by horizontal compression with factor $k$. By this I mean that every point of the graph of $y = g(x)$ is $k$ times closer to the $Oy$ axis than the corresponding point of the graph of $y = f(x)$.