D3.js geoWagner6() Function

Last Updated : 23 Sep, 2020

D3.js is a JavaScript library for producing dynamic, interactive data visualizations in web browsers. It makes use of Scalable Vector Graphics, HTML5, and Cascading Style Sheets standards.

The geoWagner6() function in d3.js is used to draw the Wagner VI projection.

Syntax:

d3.geoWagner6()

Parameters: This method does not accept any parameters.

Return Value: This method creates and returns the Wagner6 projection from given JSON data.

Example 1: The following example makes Wagner6 projection of the world with the center at (0,0) and 0 rotation.

HTML

<!DOCTYPE html>  
<html lang="en">  
  
<head>  
    <meta charset="UTF-8" />  
    <meta name="viewport"
        content="width=device-width,  
                initial-scale=1.0"/>  
  
    <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:500px;">  
        <svg width="600" height="450">  
        </svg>  
    </div>  
      
    <script> 
        var svg = d3.select("svg"), 
            width = +svg.attr("width"), 
            height = +svg.attr("height"); 
  
        // Wagner6 projection 
        // Center(0,0) with 0 rotation 
        var gfg = d3.geoWagner6() 
            .scale(width / 1.5 / Math.PI) 
            .rotate([0,0]) 
            .center([0,0]) 
            .translate([width / 2, height / 2]); 
  
        // Loading the json data 
        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", "Seagreen") 
                    .attr("d", d3.geoPath() 
                        .projection(gfg) 
                    ) 
                    .style("stroke", "#ffff") 
        }); 
    </script> 
</body>  
  
</html>

Output:

Wagner6 projection of World with no rotation and centered at (0,0)

Example 2: The following example makes Wagner6 projection of the world after customizing the center and rotation.

HTML

<!DOCTYPE html>  
<html lang="en">  
  
<head>  
    <meta charset="UTF-8" />  
    <meta name="viewport"
        content="width=device-width,  
                initial-scale=1.0"/>  
  
    <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:600px;">  
        <svg width="500" height="450">  
        </svg>  
    </div>  
      
    <script> 
        var svg = d3.select("svg"), 
            width = +svg.attr("width"), 
            height = +svg.attr("height"); 
  
        // Wagner6  projection 
        // Center(20,50) and 20 degree 
        // rotation w.r.t Y axis 
        var gfg = d3.geoWagner6() 
            .scale(width / 1.3 / Math.PI) 
            .rotate([0,20]) 
            .center([20,50]) 
            .translate([width / 2, height / 2]); 
  
        // Loading the json data 
        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", "SlateBlue") 
                    .attr("d", d3.geoPath() 
                        .projection(gfg) 
                    ) 
                    .style("stroke", "#ffff") 
        }); 
    </script> 
</body>  
  
</html>