d3.js geoNaturalEarth1()用法及代码示例

JavaScript D3.js库使用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geoNaturalEarth1()函数用于绘制自然地球投影。

用法：

d3.geoNaturalEarth1()

参数：此方法不接受任何参数。

返回：此方法根据给定的JSON数据创建“自然地球”投影。

范例1：下面的示例创建中心为(0，0)且不旋转的NaturalEarth1投影。

<!DOCTYPE html>  
<html lang="en">  
  
<head>  
    <meta charset="UTF-8" />  
    <meta name="viewport"
        content="width=device-width,  
                initial-scale=1.0"/>  
  
  
</head>  
  
<body>  
    <div style="width:700px; height:500px;">  
        <center>  
            
    
            <h3 style="color:black">  
              
            </h3>   
    
        </center> 
          
        <svg width="600" height="450">  
        </svg>  
    </div>  
    <script src="https://d3js.org/d3.v4.js"></script> 
    <script src= 
"https://d3js.org/d3-geo-projection.v2.min.js"> 
     </script> 
    <script> 
  
var svg = d3.select("svg"), 
    width = +svg.attr("width"), 
    height = +svg.attr("height"); 
  
// NaturalEarth1 projection 
// Center(0, 0) with 0 rotation 
var gfg = d3.geoNaturalEarth1() 
    .scale(width / 1.8 / 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") 
}) 
  
</script> 
</body>  
  
</html>

输出：

范例2：在以下示例中，我们将创建世界的NaturalEarth1投影，其中心位于(0，10)，并且相对于Y轴旋转60度。

<!DOCTYPE html> 
<html lang="en"> 
    <head> 
        <meta charset="UTF-8" /> 
        <meta
            name="viewport"
            content="width=device-width,  
                initial-scale=1.0" 
        /> 
    </head> 
  
    <body> 
        <div style="width:700px; height:600px;"> 
            <center> 
                <h3 style="color:black;"></h3> 
            </center> 
  
            <svg width="500" height="450"></svg> 
        </div> 
        <script src="https://d3js.org/d3.v4.js"> 
      </script> 
        <script src= 
           "https://d3js.org/d3-geo-projection.v2.min.js"> 
      </script> 
        <script> 
            var svg = d3.select("svg"), 
                width = +svg.attr("width"), 
                height = +svg.attr("height"); 
  
            // NaturalEarth1  projection 
            /*Center(0, 10) and 60 degree 
            rotation w.r.t Y axis*/ 
            var gfg = d3 
                .geoNaturalEarth1() 
                .scale(width / 1.7 / Math.PI) 
                .rotate([60, 0]) 
                .center([0, 10]) 
                .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"); 
            }); 
        </script> 
    </body> 
</html>

外出：

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 geoNaturalEarth1() 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。