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 geoFahey() function in d3.js is used to draw the Fahey pseudo cylindrical projection.
Syntax:
d3.geoFahey()
Parameters: This method does not accept any parameters.
Return Value: This method creates Fahey pseudo cylindrical projection from given json data.
Example 1: The following example makes Eckert6 projection of world with center at (0,0) and no 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= </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"); // Fahey projection // Center(0,0) with 0 rotation var gfg = d3.geoFahey() .scale(width / 1.5 / Math.PI) .rotate([0, 0]) .center([0, 0]) .translate([width / 2, height / 2]) // Loading the json data // Used json file stored at // /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", "DarkBlue") .attr("d", d3.geoPath() .projection(gfg) ) .style("stroke", "#ffff") }) </script> </body> </html> |
Output:
Fahey projection with no rotation and centered at (0,0)
Example 2: The following example makes Fahey projection of world with changing 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= </script> <script src= </script> </head> <body> <div style="width:700px; height:900px;"> <svg width="400" height="450"></svg> </div> <script> var svg = d3.select("svg"), width = +svg.attr("width"), height = +svg.attr("height"); // Fahey projection // Center(0,10) and 45 degree // anticlock rotation var gfg = d3.geoFahey() .scale(width / 1.5 / Math.PI) .rotate([45, 0]) .center([0, 10]) .translate([width / 2, height / 2]) // Loading the json data // Used json file stored at // /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", "DarkOliveGreen") .attr("d", d3.geoPath() .projection(gfg) ) .style("stroke", "#ffff") }) </script> </body> </html> |
Output:
Fahey projection with 45 degree anti-clock rotation and centered at (0,10)
