Categorical colours cube helix scale generator

forked from henryjameslau's block: Categorical colour scale generator

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>
  <script src="https://npmcdn.com/babel-core@5.8.34/browser.min.js"></script>
  <script type="text/javascript" src="https://cdn.jsdelivr.net/gh/gka/chroma.js/chroma.min.js"></script>

<body>
  <svg></svg>
  <script>
    //inspire by brian cort, you can maximise angular separation by using the golden angle 
    //https://briancort.com/colour-in-data-visualization-part-2-applications/
    
    var goldenangle = Math.round(180*(3-Math.sqrt(5)))
    var numberofcolours = 8

var colors = chroma.cubehelix()
                  .hue(1.1)
    							.start(268)
                  .rotations(numberofcolours*0.5*goldenangle)
                  .gamma(1)
                  .lightness([0.4,0.75])
                .scale() // convert to chroma.scale
                  .correctLightness()
                  .colors(numberofcolours);
      
      
    var svg = d3.select('svg');
       
    var perRow = 4;
    var size = 150;
    var g = svg.selectAll('g')
    	.data(colors).enter().append('g')
    	.attr('transform', (d, i) => {
      	var x = (i % perRow + 1) * size;
      	var y = (Math.floor(i / perRow) + 1) * size;
      	return 'translate(' + [x, y] + ')';
      }).attr('fill', d => d);
    
    g.append('circle')
    	.attr('r', size / 4);
    
    g.append('text')
    	.attr('y', size / 4 + 15)
    	.attr('text-anchor', 'middle')
    	.attr('dy', '.35em')
    	.text((d, i) => d);
  </script>
</body>

Updated missing url https://cdn.rawgit.com/gka/chroma.js/master/chroma.min.js to https://cdn.jsdelivr.net/gh/gka/chroma.js/chroma.min.js

https://d3js.org/d3.v4.min.js

https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js

https://npmcdn.com/babel-core@5.8.34/browser.min.js

https://cdn.rawgit.com/gka/chroma.js/master/chroma.min.js