The JavaScript D3.js library provides interactive data visualizations for web page using HTML5, Scalable Vector Graphics, and Cascading Style Sheets. The geoPatterson() function in d3.js is used to draw the Patterson cylindrical projection.
Syntax :
d3.geoPatterson()
Parameters: This method does not accept any parameters.
Return Value: This method creates the Patterson cylindrical projection from given JSON data.
Example 1: The following example creates Patterson 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"/> </ 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"); // Patterson projection // Center(0,0) with 0 rotation var gfg = d3.geoPatterson() .scale(width / 2.4 / 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){ // 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: In the following example, we will create Patterson projection of world with center at (0, -20) and rotating 90 degree with respect to Y axis.
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;" > < 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"); // Patterson projection // Center(0,-20) and 90 degree // rotation w.r.t Y axis var gfg = d3.geoPatterson() .scale(width / 1.7 / Math.PI) .rotate([90,0]) .center([0,-20]) .translate([width / 2, height / 2]) // Loading the json data // Used json file stored at https: //raw.githubusercontent.com/janasayantan // /datageojson/master/world.json +"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: