title: How to go from linear axis to log?
body: <p>I have a c++ program which the user will click on two points on the screen and I have to create a logarithym scale from that.. Like:</p>
  
  <p>10     100      1000      10000</p>
  
  <p>given that my first point is at 10 supossed pixel 5 and 10000 is given at pixel 200</p>
  
  <p>So how do I calculate the equation that would make my mouse show the log value when it points to the screen.</p>
  
  <p>Thanks.</p>