title: Format a number with SI Prefix, with fixed number of decimals
body: <p>I'm looking over the available type for d3.format</p>
  <blockquote>
  <p>The available type values are:</p>
  <p>exponent (&quot;e&quot;) - use Number.toExponential.</p>
  <p>general (&quot;g&quot;) - use Number.toPrecision.</p>
  <p>fixed (&quot;f&quot;) - use Number.toFixed.</p>
  <p>integer (&quot;d&quot;) - use Number.toString, but ignore any non-integer values.</p>
  <p>rounded (&quot;r&quot;) - like fixed, but round to precision significant digits.</p>
  <p>percentage (&quot;%&quot;) - like fixed, but multiply by 100 and suffix with &quot;%&quot;.</p>
  <p>rounded percentage (&quot;p&quot;) - like rounded, but multiply by 100 and suffix with &quot;%&quot;.</p>
  <p>SI-prefix (&quot;s&quot;) - <strong>like rounded</strong>, but with a unit suffixed such as &quot;9.5M&quot; or &quot;1.00µ&quot;.</p>
  </blockquote>
  <p><a href="https://github.com/mbostock/d3/wiki/Formatting#wiki-d3_format" rel="noreferrer">https://github.com/mbostock/d3/wiki/Formatting#wiki-d3_format</a></p>
  <p>What I would like is an SI-prefix that is like fixed not rounded does such a format option exist?</p>
  <p>Some examples:</p>
  <pre><code>var format = d3.format('.1s');
  format(12600000); // Would like 12.6M get 10M
  format(12400000); // Would like 12.4M get 10M
  format(1240000); // Would like 1.2M get 1M
  format(1290000); // Would like 1.3M get 1M
  </code></pre>