d3.js geoAitoff()用法及代码示例

d3.js中的geoAitoff()函数用于绘制给定geojson数据的Aitoff投影。它是一种改进的方位角投影，其中纬度和经度的线网采用椭圆形式。

用法:

d3.geoAitoff()

参数：此方法不接受任何参数。

返回：此方法返回Aitoff投影。

范例1：以下示例绘制了亚洲的Aitoff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:1000px; height:700px;"> 
        <center> 
            <h4 style="color:green" font='bold'> 
                geoAitoff Projection of Asia 
            </h4> 
        </center> 
        <svg width="650" height="350"> 
        </svg> 
    </div> 
      
    <script> 
        var svg = d3.select("svg"), 
            width = +svg.attr("width"), 
            height = +svg.attr("height"); 
  
        // geoAitoff projection 
        var gfg = d3.geoAitoff() 
            .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") 
            }); 
    </script> 
</body> 
  
</html>

输出：

范例2：以下示例绘制了世界的Aitoff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" font='bold'> 
                geoAitoff Projection of World 
            </h3> 
        </center> 
        <svg width="700" height="500"> 
        </svg> 
    </div> 
    <script> 
        var svg = d3.select("svg"), 
            width = +svg.attr("width"), 
            height = +svg.attr("height"); 
  
        // geoAitoff projection 
        var gfg = d3.geoAitoff() 
            .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", "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 geoAitoff() 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。