title: Mutiple fit lines on same plot in gnuplot?
body: <p>I'm attempting to try some simple regression lines as the basis of a gnuplot graph. However, no matter what I do, I can't get more than one fit line on a graph. Is this even possible?  Here's my (current) gnuplot program....</p>
  
  <pre><code>set title "Foo" font "Arial Bold,14"
  set term epscairo size 8,5
  set style line 1 lw 0 pt 7 lc rgb "black"
  set key outside
  set pointsize .75
  set ylabel "Y Range" font "Arial Bold"
  set xlabel "X Range" font "Arial Bold"
  set grid ytics
  set yrange [-1:100]
  set xrange [1:80]
  set output 'graph.ps'
  
  f1(x) = a1*x + b1
  fit f1(x) "data/dvdate/1" using 2:3 via a1,b1
  
  f2(x) = a1*x + b1
  fit f2(x) "data/dvdate/2" using 2:3 via a1,b1
  
  f3(x) = a1*x + b1
  fit f3(x) "data/dvdate/3" using 2:3 via a1,b1
  
  plot f1(x) title '# 1', f2(x) title '# 2', f3(x) title '# 3'
  </code></pre>
  
  <p>The result is that I have get one .ps file with one line it (not overlaying other lines) with the three data series labels.</p>