The geoCraig() function in d3.js is used to draw the Craig retroazimuthal projection from the given geojson data.
Syntax:
d3.geoCraig()
Parameters: This method does not accept any parameters.
Return Value: This method returns the Craig projection.
Example 1: The following example draws the Craig projection of the world with the center at (0, 0) and rotation of 0.
HTML
<!DOCTYPE html> < html > < head > </ script > < script src = </ script > </ head > < body > < div style = "width:700px; height:500px;" > < center > < h3 style = "color:black" ></ h3 > </ center > < svg width = "600" height = "450" > </ svg > </ div > < script > var svg = d3.select("svg"), width = +svg.attr("width"), height = +svg.attr("height"); // Craig projection // Center at (0,0) with 0 degree rotation var gfg = d3.geoCraig() .scale(width / 1.8 / 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) { // 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 > |
Output:
Example 2: The following example draws the Craig projection of the world with the center at (20, 20) and rotation of -90 degrees with respect to the y-axis.
HTML
<!DOCTYPE html> < html > < head > </ script > < script src = </ script > </ head > < body > < div style = "width:700px; height:600px;" > < center > < h3 style = "color:black" ></ h3 > </ center > < svg width = "500" height = "450" > </ svg > </ div > < script > var svg = d3.select("svg"), width = +svg.attr("width"), height = +svg.attr("height"); // Craig projection // Center at (20, 20) and // -90 degree rotation w.r.t y-axis var gfg = d3.geoCraig() .scale(width / 1.8 / Math.PI) .rotate([-90, 0]) .center([20, 20]) .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", "grey") .attr("d", d3.geoPath() .projection(gfg) ) .style("stroke", "#ffff") }); </ script > </ body > </ html > |
Output: