title: gnuplot- printing fit parameters automatically
body: <p>In gnuplot, is there a way to print the fit parameters automatically on the generated figure? For example, If I fit the data table</p>
  
  <pre><code>1   1
  2   2
  3   3
  </code></pre>
  
  <p>using:</p>
  
  <pre><code>a=1
  b=1
  f(x) = a*x + b
  fit f(x) 'data' using 1:2 via a, b
  </code></pre>
  
  <p>I'll the result <code>a=1</code> and <code>b=0</code>. I want to print them using something like</p>
  
  <pre><code>set label 'a=$a, b=$b' at (1,1)
  show label
  </code></pre>
  
  <p>The $ trick doesn't work so I hoped you could give me some tips...</p>