我使用这个stackoverflow解决方案： link

我的代码在这里.
SVG：

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JavaScript的：

var path = "289.61881571694846,291.33275072129566,286.86058614336985,286.17946205663383,116.78716653168754,279.17443456817994,116.11389849530837,272.87321137841223,271.48390485080983,126.60600357598903,267.07023512332534,268.04325927968784,264.88410671891125,132.29324106111954,113.13815447740047,282.47741986550215,108.29698566394182"
        var stringData = path.split(",");
        var length = stringData.length;
        var data = [],obj;

        for (var i = 0; i < length; i = i + 2) {
            obj = { x: parseFloat(stringData[i]),y: parseFloat(stringData[i + 1]) };
            data.push(obj);
        }

        var centerPoint = _findMidPointofPoylgon(data);
        alert("cx: " + centerPoint.x + "cy: " + centerPoint.y);

   //Return the centerX and centerY of the unshape polygon
        function _findMidPointofPoylgon (points) {
            var x = 0,y = 0,i,min = 0,j,f,point1,point2;
            var max = points.length;
            var area = function () {
                var area = 0,point2;

                for (i = 0,j = max - 1; i < max; j = i,i++) {
                    point1 = points[i];
                    point2 = points[j];
                    area += point1.x * point2.y;
                    area -= point1.y * point2.x;
                }
                area /= 2;

                return area;
            };
            for (i = 0,i++) {
                point1 = points[i];
                point2 = points[j];
                f = point1.x * point2.y - point2.x * point1.y;
                x += (point1.x + point2.x) * f;
                y += (point1.y + point2.y) * f;
            }

            f = area() * 6;
            var xSum = x / f,ySum = y / f;

            return { x: xSum,y: ySum };             
        }

我已经将方向路径数据存储在数组集合中,用于计算中心点.

Fiddle link

你能告诉我我的代码有什么问题吗？