Rotating a circle

Hi. I used JavaScript often and I sometimes use the D3 JavaScript.

But I have a question on D3 JavaScript.

What do the arguments a, x and y represents in the code below?

let svg = setupD3();
let circle = svg.append('circle').attr('r', 30).attr('fill', 'red').attr('cx', 125).attr('cy', 100);
circle.attr('transform', 'rotate(a x y)');

Please answer.

Thanks!
Pummarin :smile:

hello @pummarinbest, this is what I found
rotate(a [x y])
This transform definition specifies a rotation by a degrees about a given point. If optional parameters x and y are not supplied, the rotate is about the origin of the current user coordinate system.

If optional parameters x and y are supplied, the rotate is about the point (x, y). The operation represents the equivalent of the following transform definitions list: translate(x, y) rotate(a) translate(-x, -y).

rotate is a css attribute, it was introduced in the Responsive Web Design certification