d3.js geoArmadillo()用法及代码示例

d3.js中的geoArmadillo()函数用于绘制给定geojson数据的Armadillo投影。它是用于世界Map的Map投影，可用于显示全局大部分地区，而不是透视图的局限性。它既不是保形的也不是equal-area。中心默认为20°平行线，如果使用其他平行线，则可以更改中心线。

用法:

d3.geoArmadillo()

参数：此方法不接受任何参数。

返回值：此方法返回Armadillo投影。

范例1：以下示例绘制了世界的犰狳投影。

HTML

<!DOCTYPE html> 
<html> 
  
<head> 
    <script src= 
        "https://d3js.org/d3.v4.js"> 
    </script> 
    <script src= 
"https://d3js.org/d3-geo-projection.v2.min.js"> 
    </script> 
</head> 
  
<body> 
    <div style="width:700px; height:700px;"> 
        <center> 
            <h3 style="color:green"> 
                Armadillo Projection of World 
            </h3> 
        </center> 
        <svg width="700" height="350"> 
        </svg> 
    </div> 
      
    <script> 
        var svg = d3.select("svg"), 
            width = +svg.attr("width"), 
            height = +svg.attr("height"); 
  
        // Armadillo projection 
        var gfg = d3.geoArmadillo() 
            .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", "blue") 
                    .attr("d", d3.geoPath() 
                        .projection(gfg) 
                    ) 
                    .style("stroke", "#ffff") 
            }); 
    </script> 
</body> 
  
</html>

输出：

范例2：以下示例绘制了Armadillo亚洲投影。

HTML

<!DOCTYPE html> 
<html> 
  
<head> 
    <script src="https://d3js.org/d3.v4.js"> 
    </script> 
    <script src= 
"https://d3js.org/d3-geo-projection.v2.min.js"> 
    </script> 
</head> 
  
<body> 
    <div style="width:500px; height:700px;"> 
        <center> 
            <h3 style="color:green"> 
                Armadillo Projection of Asia 
            </h3> 
        </center> 
        <svg width="600" height="350"> 
        </svg> 
    </div> 
    <script> 
        var svg = d3.select("svg"), 
            width = +svg.attr("width"), 
            height = +svg.attr("height"); 
  
        // Armadillo projection 
        var gfg = d3.geoArmadillo() 
            .scale(width / 1.5 / Math.PI) 
            .center([100, 0]) 
            .translate([width / 2, height / 2]); 
  
        // Loading the geojson 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", "grey") 
                    .attr("d", d3.geoPath() 
                        .projection(gfg) 
                    ) 
                    .style("stroke", "#ffff"); 
            }) 
    </script> 
</body> 
  
</html>

输出：

相关用法

注：本文由纯净天空筛选整理自jana_sayantan大神的英文原创作品 D3.js geoArmadillo() Function。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。