How to make shape come back in SVG animate

Question

When I use animate with SVG tag, the desired attribute goes to the target but then suddenly comes back, i.e., it does not come back slowly, like it went. How can I make it come and go the same way. I know marquee tag but it moves the objects till the end of the page.
Thank You.
Edit: How to make it animate indefinitely?

Answer 1

Just animate it to that place and then animate it back
There’s really no other way

Answer 2

There's an easy way to do that in svg