D3.js geoCylindricalStereographic()函数

D3.js 是一个 JavaScript 库，用于在 Web 浏览器中生成动态、交互式数据可视化。它利用可缩放矢量图形、HTML5 和级联样式表标准。
d3.js 中的 CylindricalEqualArea()函数用于绘制圆柱立体投影。

句法：

d3.geoCylindricalStereographic()

参数：此方法不接受任何参数。

返回值：此方法从给定的 json 数据创建 CylindricalStereographic 投影。

示例 1：以下示例绘制了以 (0, 0) 为中心和 0 旋转的世界的 CylindricalStereographic 投影。

  

    
    

  

    
        
            
            
        
        
        
    
    
    
    
    
  
        var svg = d3.select("svg"),
            width = +svg.attr("width"),
            height = +svg.attr("height");
  
        // CylindricalStereographic projection
        // Center(0, 0) with 0 rotation
        var gfg = d3.geoCylindricalStereographic()
            .scale(width / 2.0 / Math.PI)
            .rotate([0, 0])
            .center([0, 0])
            .translate([width / 2, height / 2])
  
        // Loading the json data
        // Used json file stored at 
        // https://raw.githubusercontent.com/janasayantan
        // /datageojson/master/world.json
        d3.json("https://raw.githubusercontent.com/"
            + "janasayantan/datageojson/master/world.json",
            function (data) {
  
                // Drawing the map
                svg.append("g")
                    .selectAll("path")
                    .data(data.features)
                    .enter().append("path")
                    .attr("fill", "Black")
                    .attr("d", d3.geoPath()
                        .projection(gfg)
                    )
                    .style("stroke", "#ffff")
            })
    

  

输出：

没有旋转且以 (0, 0) 为中心的 World 的圆柱形立体投影

示例 2 ：以下示例在更改中心和旋转后绘制世界的圆柱立体投影。

  

    
    

  

    
        
            
            
        
        
        
    
    
    
    
    
  
        var svg = d3.select("svg"),
            width = +svg.attr("width"),
            height = +svg.attr("height");
  
        // CylindricalStereographic  projection
        // Center(0, 20) and 45 degree rotation w.r.t Y axis
        var gfg = d3.geoCylindricalStereographic()
            .scale(width / 2.0 / Math.PI)
            .rotate([45, 0])
            .center([0, 20])
            .translate([width / 2, height / 2])
  
        // Loading the json data
        // Used json file stored at 
        // https://raw.githubusercontent.com/janasayantan
        // /datageojson/master/world.json
        d3.json("https://raw.githubusercontent.com/"
        + "janasayantan/datageojson/master/world.json",
            function (data) {
  
                // Draw the map
                svg.append("g")
                    .selectAll("path")
                    .data(data.features)
                    .enter().append("path")
                    .attr("fill", "grey")
                    .attr("d", d3.geoPath()
                        .projection(gfg)
                    )
                    .style("stroke", "#ffff")
    

  

输出：

CylindricalEqualArea 投影，沿 Y 轴旋转 45 度并以 (0, 20) 为中心