How to set viewbox for tag, svg?

Question

JavaScript

Good afternoon! Can you please tell me how to set a viewbox or something for the svg tag?
The problem is that there is such markup.

<g><circle cx="10" cy="10" r="4"  stroke-width: 0;"></circle></g>

And I need to animate the stroke-width and when animating it turns out that the stroke-width goes beyond the g tag and the result is a square and not a circle.
How to fix it?
Thank you in advance)

Answer 1

let svg = document.getElementsByTagName('svg')[0];
svg.setAttribute('viewBox',"0 0 400 400");

But you do not need this, you need to shift g to the height and width of the future stroke-width / 2

<g transform="translate(2,2)"><circle cx="10" cy="10" r="4"  stroke-width="0"></circle></g>