title: How to plot a complex equation in Gnuplot
body: <p>I have an equation which is like this : </p>
  
  <pre><code>1/sqrt(x) = A*log(y*sqrt(x)) + B
  </code></pre>
  
  <p>I would like to use gnuplot to fit it to data I have from experiments, in a file 'niku.txt' which has my data of x and y points </p>
  
  <p>In gnuplot I write it as:</p>
  
  <pre><code>set xrange [2000 : 900000]
  g(x) = A*x + B
  fit g(x) 'niku.txt' u 1:(log($1*sqrt($2))) via A, B
  1/(g(x)*g(x)) w l ls 5 title "growth"
  
  set logscale x 
  set format x "10^%T"
  
  plot  'niku.txt'  u 1:2 w p ls 3 title "Niku " , \
        1/(g(x)*g(x)) w l ls 5 title "karman"
  </code></pre>
  
  <p>but this is not working properly, could someone tell me what mistake am making here.</p>
  
  <p><a href="https://i.stack.imgur.com/H82O8.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/H82O8.jpg" alt="plot I obtained, (x,y) plot"></a>
  Thanks </p>