title: Plot date and time (x axis) versus a value (y axis) using data from file
body: <p>I have data in a file (.dat) in the format of </p>
  
  <blockquote>
    <p>%dd %mm %yyyy %HH %MM %SS value</p>
  </blockquote>
  
  <p>separated by spaces. I would like to plot the day, month, year and time on the x-axis, and the value on the y-axis. It should always be reading it from the file, as I have many files that are very large to analyze.</p>
  
  <p>My latest attempt:</p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  import matplotlib.dates as mdates
  from time import gmtime, strftime
  date, time, level = np.loadtxt('my_file.txt', unpack=True, usecols = (0,1,2,3), converters={ 0,1: mdates.strpdate2num('%dd/%mm/%YY %HH:%MM')}) #read format of file
  # then to plot 
  plt.plot_date(x=date, y=level, fmt='%dd/%mm/%YY %HH:%MM') # fmt is changed from r- 
  plt.title('title')
  plt.ylabel('Waterlevel (m)')
  plt.grid(True)
  plt.show()
  </code></pre>