D3.js geoAiry()函数

d3.js 中的geoAiry ()函数用于从给定的geojson数据中绘制Airy 的最小误差方位角投影。这是由于地图投影中的最小化而导致的形状和面积误差的解决方案。

句法：

d3.geoAiry()

参数：此方法不接受任何参数。

返回值：此方法返回 Airy 的最小误差方位角投影。

示例 1：以下示例绘制了亚洲的艾里最小误差方位角投影。

HTML

  

    
    
    
    

  

    
        
            
                geoAiry Projection of Asia
            
        
        
        
    
    
    
        var svg = d3.select("svg"),
            width = +svg.attr("width"),
            height = +svg.attr("height");
  
        // geoAiry projection
        var gfg = d3.geoAiry()
            .scale(width / 1.5 / Math.PI)
            .translate([width / 2, height / 2]);
  
        // Loading the json data
        d3.json("https://raw.githubusercontent.com/" +
            "janasayantan/datageojson/master/" +
            "geoasia.json",
            function (data) {
  
                // Draw 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：

示例 2：以下示例绘制了艾里世界的最小误差方位角投影。

HTML

  

    
    
    
    

  

    
        
            
                azimuthal Projection of World
            
        
        
        
    
    
        var svg = d3.select("svg"),
            width = +svg.attr("width"),
            height = +svg.attr("height");
  
        // geoAiry projection
        var gfg = d3.geoAiry()
            .scale(width / 1.5 / Math.PI)
            .translate([width / 2, height / 2]);
  
        // Loading the json data
        d3.json("https://raw.githubusercontent.com/" +
            "janasayantan/datageojson/master/" +
            "geoworld%20.json",
            function (data) {
  
                // Draw the map
                svg.append("g")
                    .selectAll("path")
                    .data(data.features)
                    .enter().append("path")
                    .attr("fill", "green")
                    .attr("d", d3.geoPath()
                        .projection(gfg)
                    )
                    .style("stroke", "#ffff");
            });
    

  

输出：