title: UserWarning: Attempting to set identical left == right == [0.] results in singular transformations; automatically expanding
body: <p>def plot_activity(activity, data):</p>
  <pre><code>fig, (ax0, ax1, ax2) = plt.subplots(nrows=3, figsize=(15, 7), sharex=True)
  plot_axis(ax0, data['time'], data['x-axis'], 'X-Axis')
  plot_axis(ax1, data['time'], data['y-axis'], 'Y-Axis')
  plot_axis(ax2, data['time'], data['z-axis'], 'Z-Axis')
  plt.subplots_adjust(hspace=0.2)
  fig.suptitle(activity)
  plt.subplots_adjust(top=0.90)
  plt.show()
  </code></pre>
  <p>def plot_axis(ax, x, y, title):</p>
  <pre><code>ax.plot(x, y, 'r')
  ax.set_title(title)
  ax.xaxis.set_visible(False)
  ax.set_ylim([min(y) - np.std(y), max(y) + np.std(y)])
  ax.set_xlim([min(x), max(x)])
  ax.grid(True)
  </code></pre>
  <p>for activity in activities:
  plot_to_axis = data[data['activity'] == activity][:Fs*10]
  plot_activity(activity, plot_to_axis)</p>
  <p>Can anyone tell me where did I go wrong with this code.. I can't plot the axis</p>