Circles - option to scale

[thim81]

Is there somewhere an option to scale the circles when zooming in and out.

If heavy zoomed out the circles could be big, when zooming in the radius of the circles would schrink.

I know how to detect the

mapEvents: {
        zoom_changed: function(map, zoom) {
          console.log("map zoom changed", map.getZoom());
          console.log("zoom", zoom);
          $scope.map.radius = 1000;
        }
      },

and I tried to change the radius of the circles via the scope but the circles are not updated?