old_contents: # -*- coding: utf-8 -*-
  """Plot basic atmospheric properties conveniently.
  """
  from matplotlib import dates
  import matplotlib.pyplot as plt
  
  
  __all__ = [
      'set_date_axis',
      'timeseries',
      'heatmap',
  ]
  
  
  def set_date_axis(ax=None, dateformat='%d.%m.'):
      """Set DateFormatter for given AxesSubplot.
  
      Parameters:
          ax (AxesSubplot): Matplotlib axes.
          dateformat (str): Format string for date labels on xaxis.
      """
      formatter = dates.DateFormatter(dateformat)
      ax.xaxis.set_major_formatter(formatter)
      ax.grid('on', which='both', linestyle='-')
  
  
  def timeseries(time, data, ax=None, ylabel='', **kwargs):
      """Create a basic timeseries plot.
  
      Parameters:
          time (nd.array): Date array in matplotlib time format.
          data (nd.array): Data array.
          ax (AxesSubplot): Matplotlib axes.
          ylabel (str): y label.
          **kwargs: Additional keyword arguments passed to `plt.plot`.
  
      Returns:
          Line2D: A line.
  
      """
      if ax is None:
          ax = plt.gca()
  
      line, = ax.plot(time, data, **kwargs)
      set_date_axis(ax)
  
      ax.set_xlim(time.min(), time.max())
      ax.set_xlabel('Datum')
      ax.set_ylabel(ylabel)
      ax.legend()
  
      return line
  
  
  def heatmap(x, y, gridsize=100, rasterized=True, ax=None, **kwargs):
      """Plot a heatmap of given data.
  
      Parameters:
          x (np.ndarray): x data.
          y (np.ndarray): y data.
          gridsize (int or (int, int)):
              The number of hexagons in the *x*-direction, default is
              100. The corresponding number of hexagons in the
              *y*-direction is chosen such that the hexagons are
              approximately regular. Alternatively, gridsize can be a
              tuple with two elements specifying the number of hexagons
              in the *x*-direction and the *y*-direction.
          ax (AxesSubplot): Axes to plot in.
          **kwargs: Additional keyword argumens passed to `plt.hexbin`.
  
      Returns: Return values of `plt.hexbin`.
      """
      if ax is None:
          ax = plt.gca()
  
      def_kwargs = {
          'gridsize': gridsize,
          'rasterized': rasterized,
          'cmap': 'cubehelix_r',
          }
  
      def_kwargs.update(kwargs)
  
      return ax.hexbin(x, y, **def_kwargs)
  
new_contents: # -*- coding: utf-8 -*-
  """Plot basic atmospheric properties conveniently.
  """
  from matplotlib import dates
  import matplotlib.pyplot as plt
  
  
  __all__ = [
      'set_date_axis',
      'timeseries',
      'heatmap',
  ]
  
  
  def set_date_axis(ax=None, dateformat='%d.%m.'):
      """Set DateFormatter for given AxesSubplot.
  
      Parameters:
          ax (AxesSubplot): Matplotlib axes.
          dateformat (str): Format string for date labels on xaxis.
      """
      formatter = dates.DateFormatter(dateformat)
      ax.xaxis.set_major_formatter(formatter)
      ax.grid('on', which='both', linestyle='-')
  
  
  def timeseries(time, data, ylabel='', dateformat='%d.%m.', ax=None, **kwargs):
      """Create a basic timeseries plot.
  
      Parameters:
          time (nd.array): Date array in matplotlib time format.
          data (nd.array): Data array.
          ylabel (str): y label.
          dateformat (str): Format string for date labels on xaxis.
          ax (AxesSubplot): Matplotlib axes.
          **kwargs: Additional keyword arguments passed to `plt.plot`.
  
      Returns:
          Line2D: A line.
  
      """
      if ax is None:
          ax = plt.gca()
  
      line, = ax.plot(time, data, **kwargs)
      set_date_axis(ax, dateformat)
  
      ax.set_xlim(time.min(), time.max())
      ax.set_xlabel('Datum')
      ax.set_ylabel(ylabel)
      ax.legend()
  
      return line
  
  
  def heatmap(x, y, gridsize=100, rasterized=True, ax=None, **kwargs):
      """Plot a heatmap of given data.
  
      Parameters:
          x (np.ndarray): x data.
          y (np.ndarray): y data.
          gridsize (int or (int, int)):
              The number of hexagons in the *x*-direction, default is
              100. The corresponding number of hexagons in the
              *y*-direction is chosen such that the hexagons are
              approximately regular. Alternatively, gridsize can be a
              tuple with two elements specifying the number of hexagons
              in the *x*-direction and the *y*-direction.
          ax (AxesSubplot): Axes to plot in.
          **kwargs: Additional keyword argumens passed to `plt.hexbin`.
  
      Returns: Return values of `plt.hexbin`.
      """
      if ax is None:
          ax = plt.gca()
  
      def_kwargs = {
          'gridsize': gridsize,
          'rasterized': rasterized,
          'cmap': 'cubehelix_r',
          }
  
      def_kwargs.update(kwargs)
  
      return ax.hexbin(x, y, **def_kwargs)
  
subject: Add keyword to