D3.js geoBoggs() Function

Last Updated : 18 Sep, 2020

The geoBoggs() function in d3.js is used to draw the Boggs eumorphic projection. The Boggs eumorphic projection is a pseudo cylindrical, equal-area map projection used for world maps. It makes Boggs eumorphic projection from given geo JSON data.

Syntax:

d3.geoBoggs()

Parameters: This method does not accept any parameters.

Return Value: This method returns the Boggs projection.

Example: The following example makes the Boggs projection of Asia.

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;"> 
        <center> 
            <h4 style="color:green"> 
                Boggs Projection of Asia 
            </h4> 
        </center> 
  
        <svg width="500" height="200"> 
        </svg> 
    </div> 
  
    <script> 
        var svg = d3.select("svg"), 
            width = +svg.attr("width"), 
            height = +svg.attr("height"); 
  
        // Boggs projection 
        var gfg = d3.geoBoggs() 
            .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> 