title: gnuplot : plotting data from multiple input files in a single graph
body: <p>I am trying to plot a graph using gnuplot. I have six text files. Each text file contains two columns. The first column represents time in seconds (a floating point number). The second one is a sequence number. I want to plot the graph of time vs. sequence number in a single graph for all six files. I am using this file to do that.</p>
  
  <pre><code>set terminal png
  set output 'akamai.png'
  
  set xdata time
  set timefmt "%S"
  set xlabel "time"
  
  set autoscale
  
  set ylabel "highest seq number"
  set format y "%s"
  
  set title "seq number over time"
  set key reverse Left outside
  set grid
  
  set style data linespoints
  
  plot "print_1012720" using 1:2 title "Flow 1", \
  plot "print_1058167" using 1:2 title "Flow 2", \
  plot "print_193548"  using 1:2 title "Flow 3", \ 
  plot "print_401125"  using 1:2 title "Flow 4", \
  plot "print_401275"  using 1:2 title "Flow 5", \
  plot "print_401276"  using 1:2 title "Flow 6"
  </code></pre>
  
  <p>Where my files are:</p>
  
  <ul>
  <li><code>print_1012720</code>  </li>
  <li><code>print_1058167</code>  </li>
  <li><code>print_193548</code> </li>
  <li><code>print_401125</code> </li>
  <li><code>print_401275</code> </li>
  <li><code>print_401276</code></li>
  </ul>
  
  <p>It is giving a strange error as below:</p>
  
  <blockquote>
    <p>"plot.plt", line 24: undefined variable: plot</p>
  </blockquote>
  
  <p>Am I doing something wrong? Is it possible to plot the input data from different files in the same graph?</p>