最近几年来，地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持，如城市管理、区划、环境整治等等，地理信息成为信息时代重要的组成部分之一； “数字地球”概念的提出，更进一步推动了作为其技术支撑的GIS的发展。 与此同时，一些学者致力于相关的理论研究，如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面，并且这两个方面构成了相互促进的发展过程。
We have learned to draw a simple bar chart using ECharts in the previous section, and we will draw a pie chart in this chapter.
Pie chart is mainly through the fan-shaped Radian to show the proportion of different categories of data in the sum, its data format is simpler than thebar chart, only one-dimensional value, there is no need to give categories.Because it is not in the Cartesian coordinate system, xAxis,yAxisis not required. We can also set parameters 9.4.1. Example ¶
myChart.setOption({series:[{name:'Referrer',type:'pie',// Set chart type to pie chart radius:'55%',//The radius of the pie chart, with the outer radius being 55% of the length of the visible area size (the smaller of the container height and width). data:[//Data，name is the name of the data item，Value is the value of the data item{value:235,name:'Video AD'},{value:274,name:'Alliance advertising'},{value:310,name:'email marketing'},{value:335,name:'Direct Access'},{value:400,name:'Search Engines'}]}]}) roseType: 'angle' show the pie chart as a Nightingale chart. 9.4.2. Example ¶
option={series:[{name:'Referrer',type:'pie',radius:'55%',roseType:'angle',data:[{value:235,name:'Video AD'},{value:274,name:'Alliance advertising'},{value:310,name:'email marketing'},{value:335,name:'Direct Access'},{value:400,name:'Search Engines'}]}]};
Configuration of Shadow ¶
itemStyle parameters can be set such as shadow, transparency, color, border color, border width, and so on: 9.4.3. Example ¶
option={series:[{name:'Referrer',type:'pie',radius:'55%',data:[{value:235,name:'Video AD'},{value:274,name:'Alliance advertising'},{value:310,name:'email marketing'},{value:335,name:'Direct Access'},{value:400,name:'Search Engines'}],roseType:'angle',itemStyle:{normal:{shadowBlur:200,shadowColor:'rgba(0, 0, 0, 0.5)'}}}]};