title: Plot line with labels
body: <p>Having a plot with several traces. I want to plot one trace with labels.</p>
  
  <pre><code>plot "-" ls 3 notitle ,\
       "-" ls 4 title "Trace 1", \
       "-"  ls 5 title "Trace 2" ,\
       "-" with points ls 6 notitle
  P1 1.5 17.962924780409974
  P2 1.7 16.87322975464215
  P3 1.9 15.960477502420257
  P4 2.1 15.181442305531792
  P5 2.3000000000000003 14.506370414707312
  P6 2.5000000000000004 13.914021704740868
  P7 2.7000000000000006 13.38877362790406
  P8 2.900000000000001 12.918844829323474
  P9 3.100000000000001 12.495160353435423
  P10 3.300000000000001 12.110601416389963
  e
  ...
  </code></pre>
  
  <p>How can I plot the first traces so that <code>labels</code> with <code>P0</code> to <code>P10</code> appear next to that point?</p>