title: Plotting timeline with concurrent action by same person
body: <p>I'm looking to create a timeline plot with a number of different actors that can perform different actions, and sometimes have more than one action at the same time. As an illustration, see this mockup:</p>
  
  <p><a href="https://i.stack.imgur.com/5qOXt.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5qOXt.png" alt="Illustration of desired layout"></a></p>
  
  <p>The example illustrates that both P1 and P2 perform Activity 1 from 0:00 to 5:00. P1 then has the choice between Activities 2 and 3 between 5:00 and 17:00, while P2 has three choices, some of which also change over time.</p>
  
  <p><strong>How can I create plots like this using any arbitrary open source tool for plotting data, ideally GNUPlot (but R or matplotlib would also be fine)?</strong></p>
  
  <p>I've seen a number of similar questions (<a href="https://stackoverflow.com/questions/12941949/how-to-plot-timelines-with-r-or-gnuplot" title="1">1</a>, <a href="https://stackoverflow.com/questions/9106671/gnuplot-like-program-for-timeline-data">2</a>, <a href="https://stackoverflow.com/questions/20824024/gnuplot-making-a-stacked-barchart-in-gnuplot-with-different-colors">3</a>, <a href="https://stackoverflow.com/questions/33425785/how-to-plot-data-with-lines-like-text-datetime-with-gnuplot">4</a>, <a href="https://stackoverflow.com/questions/7684475/plotting-labeled-intervals-in-matplotlib-gnuplot?rq=1">5</a>, <a href="https://stackoverflow.com/questions/14747244/stacked-bar-plot-in-r-with-multiple-rows-per-day?rq=1">6</a>), but none of them adresses the question of concurrent actions by the same actor.</p>
  
  <p><strong>Context</strong>: The system will be used to visualize potential actions by whole groups of people. So, to give a bad example, if one group is "Students", then they may all sleep from 0:00 to 05:00, and then either work at home or work at the university until 17:00. Afterwards, they will all go back to sleep. This is not intended to be used as a Gantt chart for company planning, but to illustrate the different actions certain groups of the population may take at any time.</p>