title: Can I force bubble size ratio in D3 Bubble charts?
body: <p>I have created a webpage with up to 4 charts depending on specific criteria. Everything looks fantastic. Now the client wants the bubble-size ratio to be consistent across the 4 charts (ie. a value of 2000 is represented with the same sized bubble in every chart.)</p>
  
  <p>Is it possible to configure the <code>bubble.nodes()</code> generator to perform this task?</p>
  
  <p>I know I can provide a radius() calculator, but I don't have the mathematical background to calculate the optimal radius for a given dataset.</p>
  
  <p>I am using a pack layout. After a good night's sleep, I think I came up with a viable solution. After the layout is generated for each chart, I can find the ratio of radius to value for the largest bubble in each chart and apply a transformation <code>scale()</code> to the other SVGs to make the ratios identical (or close enough).</p>