title: Calculate the percentage of a value in a logarithmic scale
body: <p>I have a logarithmic scale going from 0 to 100:</p>
  
  <pre><code>  0.00
    0.10
    1.00
   10.00
  100.00
  </code></pre>
  
  <p>I need to make a pie chart which has 4 quarters.
  the first is going from 0 to 0.10
  the second is from 0.10 to 1  etc.etc.</p>
  
  <p>So if I have the value 25, it should be calculated which percentage this is in the logarithmic scale. Considering the scale it should end up somewhere in the last quarter of the chart.</p>
  
  <p>Unfortunately my understanding of Maths does not reach this far ;)</p>
  
  <p>Could you help out and tell me where to start.
  I thought of looking at each quarter as a 100% piece, and then calculate where this might be in this quarter..</p>
  
  <p>per example: 
  32 > 10 so it should be in the last quarter (percentage wise above 75%)</p>
  
  <p>So in this last quarter 32 will be in:</p>
  
  <pre><code>((32-10) x 100) / (100 - 10) = 24.44% in this quarter
  </code></pre>
  
  <p>Making this 24.44 / 4 = 6.11% over 4 quarters and thus 75 + 6.11 = 81.11% of the whole chart.</p>
  
  <p>Now this would work, but I am looking for a shorter and simpler way of calculating this.</p>
  
  <p>Can you please help out.</p>