How to draw circles around a circular path using D3js

Question

How to draw circles with random sizes around a circular path with D3js so that the small circles will be randomly distributed rather than overlapping with each other.

Here's how it should look:

and this is what I was able to get

jQuery(document).ready(function () { var angle, offset, data, size = [8, 15], width = 500, color = d3.scale.category10(), height = 600, radius = 200, dispersion = 10, svgContainer = d3.select('body').append("svg") .attr("width", width) .attr("height", height); data = d3.range(100).map(function () { angle = Math.random() * Math.PI * 2; offset = Math.max(size[0], size[1]) + radius + dispersion; return { cx : offset + Math.cos(angle) * radius + rand(-dispersion, dispersion), cy : offset + Math.sin(angle) * radius + rand(-dispersion, dispersion), r : rand(size[0], size[1]) }; }); svgContainer.selectAll("circle") .data(data) .enter().append("circle") .attr({ r : function (d) {return dr}, cx : function (d) {return d.cx}, cy : function (d) {return d.cy}, fill : function (d, i) {return color(i % 3)} }); function rand(min, max) { return Math.floor(Math.random() * (max - min + 1)) + min; } }); 

http://jsfiddle.net/yb8bgcrn/1/

UPDATE QUESTION

Is there a way to display it using the d3 force layout, but without links?

Answer 1

I found a solution to detect the collision function when generating random coordinates, here is the jsfiddle link and code:

  (function () { var angle, offset, data, x, y, r, collision, circle1, circle2, circles = [], size = [8, 15], width = 500, color = d3.scale.category10(), height = 600, radius = 130, dispersion = 10, svgContainer = d3.select('body').append("svg") .attr("width", width) .attr("height", height); function detectCollision(c2, c1) { var dx = c1.cx - c2.cx; var dy = c1.cy - c2.cy; var rSum = c1.r + c2.r; return ((Math.pow(dx, 2) + Math.pow(dy, 2)) < Math.pow(rSum, 2)); } var sh = 2, elements = 55; data = d3.range(elements).map(function (i) { do { // dispersion += i / 50; angle = Math.random() * Math.PI * 2; offset = Math.max(size[0], size[1]) + radius + dispersion + (elements/sh); x = offset + Math.cos(angle) * radius + rand(- (dispersion + i / sh), dispersion + i / sh); y = offset + Math.sin(angle) * radius + rand(- (dispersion + i / sh), dispersion + i / sh); r = rand(size[0], size[1]); circle2 = {cx : x, cy : y, r : r}; collision = false; if (circles.length > 1) { circles.forEach(function (d) { circle1 = {cx : d.cx, cy : d.cy, r : dr}; if (detectCollision(circle1, circle2)) { collision = true; } }); } } while (collision); circles.push(circle2); return circles[circles.length - 1]; }); svgContainer.selectAll("circle") .data(data) .enter().append("circle") .attr({ r : function (d) { return dr }, cx : function (d) { return d.cx }, cy : function (d) { return d.cy }, fill : function (d, i) { return color(i % 3) } }); function rand(min, max) { return Math.floor(Math.random() * (max - min + 1)) + min; } })(); 

Answer 2

I made some updates to your violin and applied collision detection, as in the demo mentioned in the comment. Hope this helps.

 var angle, offset, data, size = [8, 15], width = 500, color = d3.scale.category10(), height = 600, radius = 200, dispersion = 10, svgContainer = d3.select('body').append("svg") .attr("width", width) .attr("height", height); var force = d3.layout.force() .gravity(0.05) .charge(function(d, i) { return i ? 0 : -2000; }) .distance(500) .size([width, height]); data = d3.range(100).map(function() { angle = Math.random() * Math.PI * 2; offset = Math.max(size[0], size[1]) + radius + dispersion; return { x: offset + Math.cos(angle) * radius + rand(-dispersion, dispersion), y: offset + Math.sin(angle) * radius + rand(-dispersion, dispersion), radius: rand(size[0], size[1]) }; }); force .nodes(data) .start(); root = data[0], color = d3.scale.category10(); root.radius = 0; root.fixed = true; root.px = 250; //Center x root.py = 275; //Center y var nodes = svgContainer.selectAll("circle") .data(data) .enter().append("circle") .attr({ r: function(d) { return d.radius }, cx: function(d) { return dx }, cy: function(d) { return dy }, fill: function(d, i) { return color(i % 3) } }); force.on("tick", function(e) { var q = d3.geom.quadtree(data), i = 0, n = data.length; while (++i < n) q.visit(collide(data[i])); svgContainer.selectAll("circle") .attr("cx", function(d) { return dx; }) .attr("cy", function(d) { return dy; }); }); function rand(min, max) { return Math.floor(Math.random() * (max - min + 1)) + min; } function collide(node) { var r = node.radius + 16, nx1 = node.x - r, nx2 = node.x + r, ny1 = node.y - r, ny2 = node.y + r; return function(quad, x1, y1, x2, y2) { if (quad.point && (quad.point !== node)) { var x = node.x - quad.point.x, y = node.y - quad.point.y, l = Math.sqrt(x * x + y * y), r = node.radius + quad.point.radius; if (l < r) { l = (l - r) / l * .5; node.x -= x *= l; node.y -= y *= l; quad.point.x += x; quad.point.y += y; } } return x1 > nx2 || x2 < nx1 || y1 > ny2 || y2 < ny1; }; } 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script> 

EDIT

Do you mean something like this?

 var angle, offset, data, size = [8, 15], width = 500, color = d3.scale.category10(), height = 600, radius = 200, dispersion = 10, svgContainer = d3.select('body').append("svg") .attr("width", width) .attr("height", height).append("g"); var force = d3.layout.force() .gravity(0.05) .charge(function(d, i) { return i ? -20 : -2000; }) .distance(500) .size([width, height]); data = d3.range(100).map(function() { angle = Math.random() * Math.PI * 2; offset = Math.max(size[0], size[1]) + radius + dispersion; return { x: offset + Math.cos(angle) * radius + rand(-dispersion, dispersion), y: offset + Math.sin(angle) * radius + rand(-dispersion, dispersion), radius: rand(size[0], size[1]) }; }); force .nodes(data) .start(); root = data[0], color = d3.scale.category10(); root.radius = 0; root.fixed = true; root.px = 250; //Center x root.py = 275; //Center y var nodes = svgContainer.selectAll("circle") .data(data) .enter().append("circle") .attr({ r: function(d) { return d.radius }, cx: function(d) { return dx }, cy: function(d) { return dy }, fill: function(d, i) { return color(i % 3) } }); var rotation = 0; setInterval(function(){ if(force.alpha()==0){ if(!rotation) rotation = Math.random() * 50; else rotation = rotation+1; svgContainer.attr("transform","rotate("+rotation+", "+(width/2)+","+(height/2)+")"); } //force.theta(0.5); },250); force.on("tick", function(e) { var q = d3.geom.quadtree(data), i = 0, n = data.length; while (++i < n) q.visit(collide(data[i])); svgContainer.selectAll("circle") .attr("cx", function(d) { return dx; }) .attr("cy", function(d) { return dy; }); }); function rand(min, max) { return Math.floor(Math.random() * (max - min + 1)) + min; } function collide(node) { var r = node.radius + 16, nx1 = node.x - r, nx2 = node.x + r, ny1 = node.y - r, ny2 = node.y + r; return function(quad, x1, y1, x2, y2) { if (quad.point && (quad.point !== node)) { var x = node.x - quad.point.x, y = node.y - quad.point.y, l = Math.sqrt(x * x + y * y), r = node.radius + quad.point.radius; if (l < r) { l = (l - r) / l * .5; node.x -= x *= l; node.y -= y *= l; quad.point.x += x; quad.point.y += y; } } return x1 > nx2 || x2 < nx1 || y1 > ny2 || y2 < ny1; }; } 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script> 

Answer 3

Yes, you can achieve this with the power layout. The idea is that all links are displayed inactive, and the center of the node displays none. something like that:

 nodeEnter.append("circle") .style("display", function (d) { return d.children ? "none" : ""; //ceneter node has children thus display will be none }) 

In this case, it will look like the visualization you want to have.

Working code here

Hope this helps!