title: How to add a (custom) thousand separator in D3?
body: <p>I'm working with D3Plus and D3Plus accepts any D3 method.</p>
  
  <p>I could manage to remove decimals. What I cannot do is adding a '.' as a thousand separator instead of a ',' (in spanish 1.000.000 is 'one million') and this is for a spanish-speaking audience.</p>
  
  <p>This is the relevant part of my code </p>
  
  <pre><code>"number": function(number, params) {
      var formatted = d3plus.number.format(number, params);
        if (params.key === "encuentros") {
          return d3.round(number,0);
        }
        if (params.key === "poblacion") {
          return d3.round(number,0);
        }
        else {
          return formatted;
        }
    }
  </code></pre>
  
  <p>I did try <code>return d3.round(number,0) + d3.format('.')</code> but that does not work. </p>
  
  <p>The chart is "ok" but without decimal separator.</p>
  
  <p><a href="https://i.stack.imgur.com/XDBlr.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/XDBlr.jpg" alt="enter image description here"></a></p>