The JavaScript D3.js library provides interactive data visualizations for web page using HTML5, Scalable Vector Graphics, and Cascading Style Sheets. The geoNellHammer() function in d3.js is used to draw the Nell–Hammer projection.
Syntax:
d3.geoNellHammer()
Parameters: This method does not accept any parameters.
Returns: This method creates the Nell–Hammer projection from given JSON data.
Example #1: The following example creates Nell–Hammer projection of world with center at (0, 0) and no rotation.
<!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 = </ script > < script > var svg = d3.select("svg"), width = +svg.attr("width"), height = +svg.attr("height"); // Nell–Hammer projection // Center(0,0) with 0 rotation var gfg = d3.geoNellHammer() .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 /datageojson/master/world.json*/ d3.json( function(data){ // Drawing the map svg.append("g") .selectAll("path") .data(data.features) .enter().append("path") .attr("fill", "DarkSlateBlue") .attr("d", d3.geoPath() .projection(gfg) ) .style("stroke", "#ffff") }) </ script > </ body > </ html > |
Output:
Example 2: In following example we will create Nell–Hammer projection of world with center at (0, 20) and rotating -45 degree with respect to Y axis.
<!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 = </ script > < script > var svg = d3.select("svg"), width = +svg.attr("width"), height = +svg.attr("height"); // NellHammer projection // Center(0,20) and -45 degree rotation w.r.t Y axis var gfg = d3 .geoNellHammer() .scale(width / 1.7 / Math.PI) .rotate([-45, 0]) .center([0, 20]) .translate([width / 2, height / 2]); // Loading the json data // Used json file stored at /datageojson/master/world.json*/ d3.json( function (data) { // Draw the map svg.append("g").selectAll( "path").data(data.features).enter().append( "path").attr("fill", "DarkTurquoise").attr( "d", d3.geoPath().projection(gfg)).style( "stroke", "#ffff"); }); </ script > </ body > </ html > |
Output :