arc between two lat long in leaflet

function updatearc() {

  var point = [45.337, -0.472];
  var point2 = [49.045, 2.153];

  pathArcs.attr("d", function (d) {

    var source = map.latLngToLayerPoint(new L.LatLng(point[0], point[1]));
    var target = map.latLngToLayerPoint(new L.LatLng(point2[0], point2[1]));

    var dx = target.x - source.x, 
    dy = target.y - source.y, 
    dr = Math.sqrt(dx * dx + dy * dy); 

    var arc = "M" + source.x + "," + source.y + "A" + dr + "," + dr + ",0 0 1 " + target.x + "," + target.y;

    return arc;
  })
  .style({
    stroke: '#0000ff',
    'stroke-width': '20px'
  });
}