Function copy

libs/echarts/echarts-en.simple.js:932–936

* 复制向量数据 * @param {Vector2} out * @param {Vector2} v * @return {Vector2}

(out, v)

 * @return {Vector2}
 */
function copy(out, v) {
    out[0] = v[0];
    out[1] = v[1];
    return out;
}

/**
 * 克隆一个向量