function (a, b) {
                                return b.value - a.value;
                            }).slice(0, 6)),
                            symbolSize: function (val) {
                                return val[2] / 10;
                            },
                            showEffectOn: 'render',
                            rippleEffect: {
                                brushType: 'stroke'
                            },
                            hoverAnimation: true,
                      