The JavaScript library D3.js gives interactive data visualizations for web pages using HTML5, Scalable Vector Graphics and Cascading Style Sheets. The geoCollignon() function in d3.js is used to draw the collignon equal-area pseudocylindrical projection. This projection is used in the polar areas of the HEALPix projection.
Syntax:
d3.geoCollignon()
Parameters: This method does not accept any parameters.
Returns: This method creates a Collignon projection from given JSON data.
Example 1: The following example makes Collignon 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:600px;" > < svg width = "700" height = "550" > </ svg > </ div > < script > var svg = d3.select("svg"), width = +svg.attr("width"), height = +svg.attr("height"); // Collignon projection // Center(0, 0) and no rotation var gfg = d3.geoCollignon() .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", "BurlyWood") .attr("d", d3.geoPath() .projection(gfg) ) .style("stroke", "#ffff") }) </ script > </ body > </ html > |
Output: