D3.js geoEckert5()函数

JavaScript D3.js库有助于使用 HTML5、可缩放矢量图形和级联样式表为网页提供交互式数据可视化。 d3.js 中的geoEckert5 ()函数用于绘制Eckert V投影。

句法：

d3.geoEckert5()

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Eckert5投影。

示例 1：以下示例以 (0, 0) 为中心对世界进行Eckert5投影，并且没有旋转。

    
  
    
        
        
  
        
        
        
    
  
    
        
            
            
        
  
        
            var svg = d3.select("svg"),
                width = +svg.attr("width"),
                height = +svg.attr("height");
  
            // geoEckert v  projection
            // Center(0, 0) and no rotation
            var gfg = d3.geoEckert5()
                .scale(width / 1.5 / 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) {
                    // Draw the map
                    svg.append("g")
                        .selectAll("path")
                        .data(data.features)
                        .enter().append("path")
                        .attr("fill", "BurlyWood")
                        .attr("d", d3.geoPath()
                            .projection(gfg)
                        )
                        .style("stroke", "# ffff")
                })
        
    
  
    

输出：

示例 2：在下面的示例中，我们将对世界进行Eckert5投影，中心位于 (0, 0) 并相对于 Y 轴逆时针旋转 45 度。

HTML

  

    
    
    
    
    

  

    
  
        
        
    
  
    
        var svg = d3.select("svg"),
            width = +svg.attr("width"),
            height = +svg.attr("height");
  
        // geoEckert IV  projection
        // Center(0, 0) and  rotating 45
        // degree anti-clockwise
        var gfg = d3.geoEckert5()
            .scale(width / 1.5 / Math.PI)
            .rotate([-45, 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) {
                // 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：