title: Finding fitting range using gnuplot
body: <p>I am new to Gnuplot, I have a non-linear data set and I want to fit the data within the linear range only. I normally do the fitting and specifies the fit range using the following command and redo the fitting process by changing the fit range manually until I get the optimum range for the fit:</p>
  <pre><code>fit [0.2:0.6]f(x) &quot;data.txt&quot; u 2:3:6 yerror via m1,m2 
  
  plot &quot;&lt;(sed -n '15,500p' data.txt)&quot; u 2:3:6 w yerr title 'Window A',[0:.6] f(x) notitle lc rgb 'black'
  </code></pre>
  <p>Is it possible to iteratively run the fit within some data range to obtain the optimum data range for the fit in Gnuplot?</p>
  <p>The data is typically like this one:
  <a href="https://icedrive.net/0/0ciJPoO6Om" rel="nofollow noreferrer">data</a></p>